flutter pub get is failing

user@user-Latitude-3500:~/flutter_projects$ flutter doctor
Doctor summary (to see all details, run flutter doctor -v):
[✓] Flutter (Channel stable, v1.17.5, on Linux, locale en_IN)
[✓] Android toolchain - develop for Android devices (Android SDK version 30.0.1)
[✓] Android Studio (version 4.0)
[!] Connected device
    ! No devices available

! Doctor found issues in 1 category.
user@user-Latitude-3500:~/flutter_projects$
user@user-Latitude-3500:~/flutter_projects$
user@user-Latitude-3500:~/flutter_projects$
user@user-Latitude-3500:~/flutter_projects$
user@user-Latitude-3500:~/flutter_projects$
user@user-Latitude-3500:~/flutter_projects$ flutter -v create testapp
[  +15 ms] executing: [/home/user/snap/flutter/common/flutter/] git -c log.showSignature=false log -n 1 --pretty=format:%H
[  +37 ms] Exit code 0 from: git -c log.showSignature=false log -n 1 --pretty=format:%H
[        ] 8af6b2f038c1172e61d418869363a28dffec3cb4
[        ] executing: [/home/user/snap/flutter/common/flutter/] git tag --contains HEAD
[ +279 ms] Exit code 0 from: git tag --contains HEAD
[   +3 ms] 1.17.5
[  +10 ms] executing: [/home/user/snap/flutter/common/flutter/] git rev-parse --abbrev-ref --symbolic @{u}
[   +4 ms] Exit code 0 from: git rev-parse --abbrev-ref --symbolic @{u}
[        ] origin/stable
[        ] executing: [/home/user/snap/flutter/common/flutter/] git ls-remote --get-url origin
[   +4 ms] Exit code 0 from: git ls-remote --get-url origin
[        ] https://github.com/flutter/flutter.git
[ +114 ms] executing: [/home/user/snap/flutter/common/flutter/] git rev-parse --abbrev-ref HEAD
[   +7 ms] Exit code 0 from: git rev-parse --abbrev-ref HEAD
[        ] stable
[  +38 ms] Artifact Instance of 'AndroidMavenArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'AndroidGenSnapshotArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'AndroidInternalBuildArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'IOSEngineArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'FlutterWebSdk' is not required, skipping update.
[   +3 ms] Artifact Instance of 'WindowsEngineArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'MacOSEngineArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'LinuxEngineArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'LinuxFuchsiaSDKArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'MacOSFuchsiaSDKArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'FlutterRunnerSDKArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'FlutterRunnerDebugSymbols' is not required, skipping update.
[  +11 ms] Artifact Instance of 'MaterialFonts' is not required, skipping update.
[        ] Artifact Instance of 'GradleWrapper' is not required, skipping update.
[        ] Artifact Instance of 'AndroidMavenArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'AndroidGenSnapshotArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'AndroidInternalBuildArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'IOSEngineArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'FlutterWebSdk' is not required, skipping update.
[        ] Artifact Instance of 'FlutterSdk' is not required, skipping update.
[        ] Artifact Instance of 'WindowsEngineArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'MacOSEngineArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'LinuxEngineArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'LinuxFuchsiaSDKArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'MacOSFuchsiaSDKArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'FlutterRunnerSDKArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'FlutterRunnerDebugSymbols' is not required, skipping update.
[        ] Artifact Instance of 'IosUsbArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'IosUsbArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'IosUsbArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'IosUsbArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'IosUsbArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'FontSubsetArtifacts' is not required, skipping update.
[  +81 ms] Creating project testapp...
[  +40 ms]   testapp/test/widget_test.dart (created)
[  +21 ms]   testapp/.gitignore (created)
[   +1 ms]   testapp/README.md (created)
[   +1 ms]   testapp/android/app/src/debug/AndroidManifest.xml (created)
[   +1 ms]   testapp/android/app/src/main/AndroidManifest.xml (created)
[   +4 ms]   testapp/android/app/src/main/res/values/styles.xml (created)
[   +1 ms]   testapp/android/app/src/main/res/drawable/launch_background.xml (created)
[        ]   testapp/android/app/src/main/res/mipmap-xxhdpi/ic_launcher.png (created)
[        ]   testapp/android/app/src/main/res/mipmap-mdpi/ic_launcher.png (created)
[        ]   testapp/android/app/src/main/res/mipmap-hdpi/ic_launcher.png (created)
[        ]   testapp/android/app/src/main/res/mipmap-xxxhdpi/ic_launcher.png (created)
[        ]   testapp/android/app/src/main/res/mipmap-xhdpi/ic_launcher.png (created)
[        ]   testapp/android/app/src/profile/AndroidManifest.xml (created)
[   +1 ms]   testapp/android/gradle.properties (created)
[   +1 ms]   testapp/android/settings.gradle (created)
[        ]   testapp/android/.gitignore (created)
[        ]   testapp/android/gradle/wrapper/gradle-wrapper.properties (created)
[        ]   testapp/pubspec.yaml (created)
[   +2 ms]   testapp/.idea/runConfigurations/main_dart.xml (created)
[   +1 ms]   testapp/.idea/workspace.xml (created)
[   +1 ms]   testapp/.idea/libraries/Flutter_for_Android.xml (created)
[   +1 ms]   testapp/.idea/libraries/Dart_SDK.xml (created)
[   +1 ms]   testapp/.idea/libraries/KotlinJavaRuntime.xml (created)
[   +1 ms]   testapp/.idea/modules.xml (created)
[   +1 ms]   testapp/ios/Runner.xcodeproj/xcshareddata/xcschemes/Runner.xcscheme (created)
[   +1 ms]   testapp/ios/Runner.xcodeproj/project.xcworkspace/xcshareddata/WorkspaceSettings.xcsettings (created)
[        ]   testapp/ios/Runner.xcodeproj/project.xcworkspace/xcshareddata/IDEWorkspaceChecks.plist (created)
[        ]   testapp/ios/Runner.xcodeproj/project.xcworkspace/contents.xcworkspacedata (created)
[        ]   testapp/ios/Flutter/Debug.xcconfig (created)
[        ]   testapp/ios/Flutter/AppFrameworkInfo.plist (created)
[        ]   testapp/ios/Flutter/Release.xcconfig (created)
[        ]   testapp/ios/Runner.xcworkspace/xcshareddata/WorkspaceSettings.xcsettings (created)
[        ]   testapp/ios/Runner.xcworkspace/xcshareddata/IDEWorkspaceChecks.plist (created)
[        ]   testapp/ios/Runner.xcworkspace/contents.xcworkspacedata (created)
[        ]   testapp/ios/.gitignore (created)
[        ]<EMAIL_ADDRESS>(created)
[        ]<EMAIL_ADDRESS>(created)
[   +1 ms]<EMAIL_ADDRESS>(created)
[        ]<EMAIL_ADDRESS>(created)
[        ]   testapp/ios/Runner/Assets.xcassets/AppIcon.appiconset/Contents.json (created)
[        ]<EMAIL_ADDRESS>(created)
[        ]<EMAIL_ADDRESS>(created)
[        ]<EMAIL_ADDRESS>(created)
[        ]<EMAIL_ADDRESS>(created)
[        ]<EMAIL_ADDRESS>(created)
[        ]<EMAIL_ADDRESS>(created)
[        ]<EMAIL_ADDRESS>(created)
[        ]<EMAIL_ADDRESS>(created)
[        ]<EMAIL_ADDRESS>(created)
[        ]<EMAIL_ADDRESS>(created)
[        ]<EMAIL_ADDRESS>(created)
[        ]<EMAIL_ADDRESS>(created)
[        ]   testapp/ios/Runner/Assets.xcassets/LaunchImage.imageset/Contents.json (created)
[        ]   testapp/ios/Runner/Assets.xcassets/LaunchImage.imageset/LaunchImage.png (created)
[        ]   testapp/ios/Runner/Assets.xcassets/LaunchImage.imageset/README.md (created)
[        ]<EMAIL_ADDRESS>(created)
[        ]   testapp/ios/Runner/Base.lproj/Main.storyboard (created)
[        ]   testapp/ios/Runner/Base.lproj/LaunchScreen.storyboard (created)
[        ]   testapp/ios/Runner/Info.plist (created)
[   +1 ms]   testapp/testapp.iml (created)
[        ]   testapp/lib/main.dart (created)
[   +2 ms]   testapp/ios/Runner.xcodeproj/xcshareddata/xcschemes/Runner.xcscheme (existing - skipped)
[        ]   testapp/ios/Runner.xcodeproj/project.pbxproj (created)
[   +9 ms]   testapp/ios/Runner/Runner-Bridging-Header.h (created)
[        ]   testapp/ios/Runner/AppDelegate.swift (created)
[        ]   testapp/.metadata (created)
[        ]   testapp/android/app/build.gradle (created)
[   +1 ms]   testapp/android/app/src/main/kotlin/com/example/testapp/MainActivity.kt (created)
[   +1 ms]   testapp/android/testapp_android.iml (created)
[   +1 ms]   testapp/android/build.gradle (created)
[  +65 ms] Running "flutter pub get" in testapp...
[   +5 ms] Using /home/user/snap/flutter/common/flutter/.pub-cache for the pub cache.
[   +1 ms] executing: [/home/user/flutter_projects/testapp/] /home/user/snap/flutter/common/flutter/bin/cache/dart-sdk/bin/pub --verbose get
--no-precompile
[  +87 ms] FINE: Pub 2.8.4
[  +74 ms] MSG : Resolving dependencies...
[  +17 ms] SLVR: fact: testapp is 1.0.0+1
[   +7 ms] SLVR: derived: testapp
[  +36 ms] SLVR: fact: testapp depends on flutter any from sdk
[        ] SLVR: fact: testapp depends on cupertino_icons ^0.1.3
[        ] SLVR: fact: testapp depends on flutter_test any from sdk
[   +1 ms] SLVR:   selecting testapp
[        ] SLVR:   derived: flutter_test any from sdk
[        ] SLVR:   derived: cupertino_icons ^0.1.3
[        ] SLVR:   derived: flutter any from sdk
[  +41 ms] IO  : Get versions from https://pub.dartlang.org/api/packages/cupertino_icons.
[  +27 ms] IO  : HTTP GET https://pub.dartlang.org/api/packages/cupertino_icons
[        ]     | Accept: application/vnd.pub.v2+json
[        ]     | X-Pub-OS: linux
[        ]     | X-Pub-Command: get
[        ]     | X-Pub-Session-ID: 755B54F3-5D95-4F69-8123-56CF8A9F11ED
[        ]     | X-Pub-Environment: flutter_cli:create
[        ]     | X-Pub-Reason: direct
[        ]     | user-agent: Dart pub 2.8.4
[+130605 ms] IO  : HTTP error:
[        ]     | SocketException: OS Error: Connection timed out, errno = 110, address = pub.dartlang.org, port = 45742
[        ]     |
[        ]     | dart:_http                                          _HttpClient.openUrl
[        ]     | package:http/src/io_client.dart 33:36               IOClient.send
[        ]     | package:pub/src/http.dart 66:43                     _PubHttpClient.send
[        ]     | package:http_retry/http_retry.dart 97:33            RetryClient.send
[        ]     | package:pub/src/http.dart 165:39                    _ThrowingClient.send
[        ]     | package:http_throttle/http_throttle.dart 33:31      ThrottleClient.send
[        ]     | ===== asynchronous gap ===========================
[        ]     | dart:async                                          _asyncThenWrapperHelper
[        ]     | package:http/src/base_client.dart 169:38            BaseClient._sendUnstreamed
[        ]     | package:http/src/base_client.dart 32:7              BaseClient.get
[        ]     | package:http/src/base_client.dart 117:12            BaseClient.read
[        ]     | package:pub/src/source/hosted.dart 185:31           BoundHostedSource._fetchVersions
[        ]     | dart:async                                          _CustomZone.runUnary
[        ]     | package:pub/src/rate_limited_scheduler.dart 82:30   RateLimitedScheduler._processNextTask.runJob
[        ]     | package:pub/src/rate_limited_scheduler.dart 85:30   RateLimitedScheduler._processNextTask
[        ]     | dart:async                                          new Future.sync
[        ]     | package:pool/pool.dart 126:18                       Pool.withResource.<fn>
[        ]     | ===== asynchronous gap ===========================
[        ]     | dart:async                                          Future.then
[        ]     | package:pool/pool.dart 125:22                       Pool.withResource
[        ]     | package:pub/src/rate_limited_scheduler.dart 129:37  RateLimitedScheduler.schedule.<fn>
[        ]     | ===== asynchronous gap ===========================
[        ]     | dart:async                                          scheduleMicrotask
[        ]     | package:pub/src/rate_limited_scheduler.dart 129:7   RateLimitedScheduler.schedule
[        ]     | package:pub/src/source/hosted.dart 231:39           BoundHostedSource.doGetVersions
[        ]     | package:pub/src/source.dart 168:12                  BoundSource.getVersions
[        ]     | package:pub/src/solver/package_lister.dart 76:44    PackageLister._versions.<fn>.<fn>
[        ]     | dart:async                                          runZoned
[        ]     | package:pub/src/http.dart 279:10                    withDependencyType
[        ]     | package:pub/src/solver/package_lister.dart 75:33    PackageLister._versions.<fn>
[        ]     | dart:async                                          new Future.sync
[        ]     | package:async/src/async_memoizer.dart 43:45         AsyncMemoizer.runOnce
[        ]     | package:pub/src/solver/package_lister.dart 74:58    PackageLister._versions
[        ]     | package:pub/src/solver/package_lister.dart 111:21   PackageLister.countVersions
[        ]     | package:pub/src/solver/version_solver.dart 356:44   VersionSolver._choosePackageVersion.<fn>
[        ]     | dart:async                                          Future.wait
[        ]     | package:pub/src/utils.dart 295:39                   minByAsync
[        ]     | package:pub/src/solver/version_solver.dart 352:25   VersionSolver._choosePackageVersion
[        ]     | package:pub/src/solver/version_solver.dart 98:24    VersionSolver.solve.<fn>
[        ]     | dart:async                                          _completeOnAsyncReturn
[        ]     | package:pub/src/solver/version_solver.dart          VersionSolver._choosePackageVersion
[        ]     | dart:async                                          _completeOnAsyncReturn
[        ]     | package:pub/src/solver/package_lister.dart          PackageLister.incompatibilitiesFor
[        ]     | ===== asynchronous gap ===========================
[        ]     | dart:async                                          _asyncThenWrapperHelper
[        ]     | package:pub/src/solver/version_solver.dart          VersionSolver.solve.<fn>
[        ]     | dart:async                                          runZoned
[        ]     | package:pub/src/source/hosted.dart 502:20           BoundHostedSource.withPrefetching.<fn>
[        ]     | package:pub/src/rate_limited_scheduler.dart 105:28  RateLimitedScheduler.withPrescheduling
[        ]     | package:pub/src/source/hosted.dart 501:29           BoundHostedSource.withPrefetching
[        ]     | package:pub/src/solver/version_solver.dart 94:40    VersionSolver.solve
[        ]     | package:pub/src/solver.dart 37:5                    resolveVersions
[        ]     | package:pub/src/entrypoint.dart 218:13              Entrypoint.acquireDependencies.<fn>
[        ]     | package:pub/src/log.dart 394:18                     progress
[        ]     | package:pub/src/entrypoint.dart 216:24              Entrypoint.acquireDependencies
[        ]     | package:pub/src/command/get.dart 46:23              GetCommand.run
[        ]     | package:args/command_runner.dart 197:27             CommandRunner.runCommand
[        ]     | package:pub/src/command_runner.dart 191:39          PubCommandRunner.runCommand.<fn>
[        ]     | dart:async                                          new Future.sync
[        ]     | package:pub/src/utils.dart 113:12                   captureErrors.wrappedCallback
[        ]     | package:stack_trace                                 Chain.capture
[        ]     | package:pub/src/utils.dart 126:11                   captureErrors
[        ]     | package:pub/src/command_runner.dart 191:13          PubCommandRunner.runCommand
[ +956 ms] IO  : Retry #1 for GET https://pub.dartlang.org/api/packages/cupertino_icons...
[   +1 ms] IO  : HTTP GET https://pub.dartlang.org/api/packages/cupertino_icons
[        ]     | Accept: application/vnd.pub.v2+json
[        ]     | X-Pub-OS: linux
[        ]     | X-Pub-Command: get
[        ]     | X-Pub-Session-ID: 755B54F3-5D95-4F69-8123-56CF8A9F11ED
[        ]     | X-Pub-Environment: flutter_cli:create
[   +2 ms]     | X-Pub-Reason: direct
[        ]     | user-agent: Dart pub 2.8.4
[+130041 ms] IO  : HTTP error:
[        ]     | SocketException: OS Error: Connection timed out, errno = 110, address = pub.dartlang.org, port = 45746
[        ]     |
[        ]     | dart:_http                                          _HttpClient.openUrl
[        ]     | package:http/src/io_client.dart 33:36               IOClient.send
[        ]     | package:pub/src/http.dart 66:43                     _PubHttpClient.send
[        ]     | package:http_retry/http_retry.dart 97:33            RetryClient.send
[        ]     | ===== asynchronous gap ===========================
[        ]     | dart:async                                          _asyncThenWrapperHelper
[        ]     | package:pub/src/http.dart 165:39                    _ThrowingClient.send
[        ]     | package:http_throttle/http_throttle.dart 33:31      ThrottleClient.send
[        ]     | ===== asynchronous gap ===========================
[        ]     | dart:async                                          _asyncThenWrapperHelper
[        ]     | package:http/src/base_client.dart 169:38            BaseClient._sendUnstreamed
[        ]     | package:http/src/base_client.dart 32:7              BaseClient.get
[        ]     | package:http/src/base_client.dart 117:12            BaseClient.read
[        ]     | package:pub/src/source/hosted.dart 185:31           BoundHostedSource._fetchVersions
[        ]     | dart:async                                          _CustomZone.runUnary
[        ]     | package:pub/src/rate_limited_scheduler.dart 82:30   RateLimitedScheduler._processNextTask.runJob
[        ]     | package:pub/src/rate_limited_scheduler.dart 85:30   RateLimitedScheduler._processNextTask
[        ]     | dart:async                                          new Future.sync
[        ]     | package:pool/pool.dart 126:18                       Pool.withResource.<fn>
[        ]     | ===== asynchronous gap ===========================
[        ]     | dart:async                                          Future.then
[        ]     | package:pool/pool.dart 125:22                       Pool.withResource
[        ]     | package:pub/src/rate_limited_scheduler.dart 129:37  RateLimitedScheduler.schedule.<fn>
[        ]     | ===== asynchronous gap ===========================
[        ]     | dart:async                                          scheduleMicrotask
[        ]     | package:pub/src/rate_limited_scheduler.dart 129:7   RateLimitedScheduler.schedule
[        ]     | package:pub/src/source/hosted.dart 231:39           BoundHostedSource.doGetVersions
[        ]     | package:pub/src/source.dart 168:12                  BoundSource.getVersions
[        ]     | package:pub/src/solver/package_lister.dart 76:44    PackageLister._versions.<fn>.<fn>
[        ]     | dart:async                                          runZoned
[        ]     | package:pub/src/http.dart 279:10                    withDependencyType
[        ]     | package:pub/src/solver/package_lister.dart 75:33    PackageLister._versions.<fn>
[        ]     | dart:async                                          new Future.sync
[        ]     | package:async/src/async_memoizer.dart 43:45         AsyncMemoizer.runOnce
[        ]     | package:pub/src/solver/package_lister.dart 74:58    PackageLister._versions
[        ]     | package:pub/src/solver/package_lister.dart 111:21   PackageLister.countVersions
[        ]     | package:pub/src/solver/version_solver.dart 356:44   VersionSolver._choosePackageVersion.<fn>
[        ]     | dart:async                                          Future.wait
[        ]     | package:pub/src/utils.dart 295:39                   minByAsync
[        ]     | package:pub/src/solver/version_solver.dart 352:25   VersionSolver._choosePackageVersion
[        ]     | package:pub/src/solver/version_solver.dart 98:24    VersionSolver.solve.<fn>
[        ]     | dart:async                                          _completeOnAsyncReturn
[        ]     | package:pub/src/solver/version_solver.dart          VersionSolver._choosePackageVersion
[        ]     | dart:async                                          _completeOnAsyncReturn
[        ]     | package:pub/src/solver/package_lister.dart          PackageLister.incompatibilitiesFor
[        ]     | ===== asynchronous gap ===========================
[        ]     | dart:async                                          _asyncThenWrapperHelper
[        ]     | package:pub/src/solver/version_solver.dart          VersionSolver.solve.<fn>
[        ]     | dart:async                                          runZoned
[        ]     | package:pub/src/source/hosted.dart 502:20           BoundHostedSource.withPrefetching.<fn>
[        ]     | package:pub/src/rate_limited_scheduler.dart 105:28  RateLimitedScheduler.withPrescheduling
[        ]     | package:pub/src/source/hosted.dart 501:29           BoundHostedSource.withPrefetching
[        ]     | package:pub/src/solver/version_solver.dart 94:40    VersionSolver.solve
[        ]     | package:pub/src/solver.dart 37:5                    resolveVersions
[        ]     | package:pub/src/entrypoint.dart 218:13              Entrypoint.acquireDependencies.<fn>
[        ]     | package:pub/src/log.dart 394:18                     progress
[        ]     | package:pub/src/entrypoint.dart 216:24              Entrypoint.acquireDependencies
[        ]     | package:pub/src/command/get.dart 46:23              GetCommand.run
[        ]     | package:args/command_runner.dart 197:27             CommandRunner.runCommand
[        ]     | package:pub/src/command_runner.dart 191:39          PubCommandRunner.runCommand.<fn>
[        ]     | dart:async                                          new Future.sync
[        ]     | package:pub/src/utils.dart 113:12                   captureErrors.wrappedCallback
[        ]     | package:stack_trace                                 Chain.capture
[        ]     | package:pub/src/utils.dart 126:11                   captureErrors
[        ]     | package:pub/src/command_runner.dart 191:13          PubCommandRunner.runCommand
[ +912 ms] IO  : Retry #2 for GET https://pub.dartlang.org/api/packages/cupertino_icons...
[   +1 ms] IO  : HTTP GET https://pub.dartlang.org/api/packages/cupertino_icons
[        ]     | Accept: application/vnd.pub.v2+json
[        ]     | X-Pub-OS: linux
[        ]     | X-Pub-Command: get
[        ]     | X-Pub-Session-ID: 755B54F3-5D95-4F69-8123-56CF8A9F11ED
[        ]     | X-Pub-Environment: flutter_cli:create
[        ]     | X-Pub-Reason: direct
[        ]     | user-agent: Dart pub 2.8.4
[+130137 ms] IO  : HTTP error:
[        ]     | SocketException: OS Error: Connection timed out, errno = 110, address = pub.dartlang.org, port = 45748
[        ]     |
[        ]     | dart:_http                                          _HttpClient.openUrl
[        ]     | package:http/src/io_client.dart 33:36               IOClient.send
[        ]     | package:pub/src/http.dart 66:43                     _PubHttpClient.send
[        ]     | package:http_retry/http_retry.dart 97:33            RetryClient.send
[        ]     | ===== asynchronous gap ===========================
[        ]     | dart:async                                          _asyncThenWrapperHelper
[        ]     | package:pub/src/http.dart 165:39                    _ThrowingClient.send
[        ]     | package:http_throttle/http_throttle.dart 33:31      ThrottleClient.send
[        ]     | ===== asynchronous gap ===========================
[        ]     | dart:async                                          _asyncThenWrapperHelper
[        ]     | package:http/src/base_client.dart 169:38            BaseClient._sendUnstreamed
[        ]     | package:http/src/base_client.dart 32:7              BaseClient.get
[        ]     | package:http/src/base_client.dart 117:12            BaseClient.read
[        ]     | package:pub/src/source/hosted.dart 185:31           BoundHostedSource._fetchVersions
[        ]     | dart:async                                          _CustomZone.runUnary
[        ]     | package:pub/src/rate_limited_scheduler.dart 82:30   RateLimitedScheduler._processNextTask.runJob
[        ]     | package:pub/src/rate_limited_scheduler.dart 85:30   RateLimitedScheduler._processNextTask
[        ]     | dart:async                                          new Future.sync
[        ]     | package:pool/pool.dart 126:18                       Pool.withResource.<fn>
[        ]     | ===== asynchronous gap ===========================
[        ]     | dart:async                                          Future.then
[        ]     | package:pool/pool.dart 125:22                       Pool.withResource
[        ]     | package:pub/src/rate_limited_scheduler.dart 129:37  RateLimitedScheduler.schedule.<fn>
[        ]     | ===== asynchronous gap ===========================
[        ]     | dart:async                                          scheduleMicrotask
[        ]     | package:pub/src/rate_limited_scheduler.dart 129:7   RateLimitedScheduler.schedule
[        ]     | package:pub/src/source/hosted.dart 231:39           BoundHostedSource.doGetVersions
[        ]     | package:pub/src/source.dart 168:12                  BoundSource.getVersions
[        ]     | package:pub/src/solver/package_lister.dart 76:44    PackageLister._versions.<fn>.<fn>
[        ]     | dart:async                                          runZoned
[        ]     | package:pub/src/http.dart 279:10                    withDependencyType
[        ]     | package:pub/src/solver/package_lister.dart 75:33    PackageLister._versions.<fn>
[        ]     | dart:async                                          new Future.sync
[        ]     | package:async/src/async_memoizer.dart 43:45         AsyncMemoizer.runOnce
[        ]     | package:pub/src/solver/package_lister.dart 74:58    PackageLister._versions
[        ]     | package:pub/src/solver/package_lister.dart 111:21   PackageLister.countVersions
[        ]     | package:pub/src/solver/version_solver.dart 356:44   VersionSolver._choosePackageVersion.<fn>
[        ]     | dart:async                                          Future.wait
[        ]     | package:pub/src/utils.dart 295:39                   minByAsync
[        ]     | package:pub/src/solver/version_solver.dart 352:25   VersionSolver._choosePackageVersion
[        ]     | package:pub/src/solver/version_solver.dart 98:24    VersionSolver.solve.<fn>
[        ]     | dart:async                                          _completeOnAsyncReturn
[        ]     | package:pub/src/solver/version_solver.dart          VersionSolver._choosePackageVersion
[        ]     | dart:async                                          _completeOnAsyncReturn
[        ]     | package:pub/src/solver/package_lister.dart          PackageLister.incompatibilitiesFor
[        ]     | ===== asynchronous gap ===========================
[        ]     | dart:async                                          _asyncThenWrapperHelper
[        ]     | package:pub/src/solver/version_solver.dart          VersionSolver.solve.<fn>
[        ]     | dart:async                                          runZoned
[        ]     | package:pub/src/source/hosted.dart 502:20           BoundHostedSource.withPrefetching.<fn>
[        ]     | package:pub/src/rate_limited_scheduler.dart 105:28  RateLimitedScheduler.withPrescheduling
[        ]     | package:pub/src/source/hosted.dart 501:29           BoundHostedSource.withPrefetching
[        ]     | package:pub/src/solver/version_solver.dart 94:40    VersionSolver.solve
[        ]     | package:pub/src/solver.dart 37:5                    resolveVersions
[        ]     | package:pub/src/entrypoint.dart 218:13              Entrypoint.acquireDependencies.<fn>
[        ]     | package:pub/src/log.dart 394:18                     progress
[        ]     | package:pub/src/entrypoint.dart 216:24              Entrypoint.acquireDependencies
[        ]     | package:pub/src/command/get.dart 46:23              GetCommand.run
[        ]     | package:args/command_runner.dart 197:27             CommandRunner.runCommand
[        ]     | package:pub/src/command_runner.dart 191:39          PubCommandRunner.runCommand.<fn>
[        ]     | dart:async                                          new Future.sync
[        ]     | package:pub/src/utils.dart 113:12                   captureErrors.wrappedCallback
[        ]     | package:stack_trace                                 Chain.capture
[        ]     | package:pub/src/utils.dart 126:11                   captureErrors
[        ]     | package:pub/src/command_runner.dart 191:13          PubCommandRunner.runCommand
[+1267 ms] IO  : Retry #3 for GET https://pub.dartlang.org/api/packages/cupertino_icons...
[        ] IO  : HTTP GET https://pub.dartlang.org/api/packages/cupertino_icons
[        ]     | Accept: application/vnd.pub.v2+json
[        ]     | X-Pub-OS: linux
[        ]     | X-Pub-Command: get
[        ]     | X-Pub-Session-ID: 755B54F3-5D95-4F69-8123-56CF8A9F11ED
[        ]     | X-Pub-Environment: flutter_cli:create
[        ]     | X-Pub-Reason: direct
[        ]     | user-agent: Dart pub 2.8.4
^Cuser@user-Latitude-3500:~/flutter_projects$

Have you checked your internet? You need to connect your PC to internet while using pub get

Yes. Internet is working perfectly.
I think the issue is with below. But not sure.
[  +36 ms] SLVR: fact: testapp depends on flutter any from sdk
[        ] SLVR: fact: testapp depends on cupertino_icons ^0.1.3
[        ] SLVR: fact: testapp depends on flutter_test any from sdk

On stack-overflow, some answers recommended to switch to dev channel.
https://stackoverflow.com/a/51376009
https://stackoverflow.com/a/51717690
https://stackoverflow.com/a/59154244
I did switch to dev channel. But still exits.
user@user-Latitude-3500:~/flutter_projects$ flutter channel
    Flutter channels:
      master
      dev
      beta
    * stable
    user@user-Latitude-3500:~/flutter_projects$
    user@user-Latitude-3500:~/flutter_projects$
    user@user-Latitude-3500:~/flutter_projects$
    user@user-Latitude-3500:~/flutter_projects$
    user@user-Latitude-3500:~/flutter_projects$ flutter channel dev
    Switching to flutter channel 'dev'...
    git: From https://github.com/flutter/flutter
    git:  * [new branch]          dds_support_take4 -> origin/dds_support_take4
    git:  * [new branch]          flutter-1.21-candidate.4 -> origin/flutter-1.21-candidate.4
    git: Switched to a new branch 'dev'
    git: Branch 'dev' set up to track remote branch 'dev' from 'origin'.
    Successfully switched to flutter channel 'dev'.
    To ensure that you're on the latest build from this channel, run 'flutter upgrade'
    user@user-Latitude-3500:~/flutter_projects$
    user@user-Latitude-3500:~/flutter_projects$
    user@user-Latitude-3500:~/flutter_projects$
    user@user-Latitude-3500:~/flutter_projects$
    user@user-Latitude-3500:~/flutter_projects$
    user@user-Latitude-3500:~/flutter_projects$
    user@user-Latitude-3500:~/flutter_projects$
    user@user-Latitude-3500:~/flutter_projects$
    user@user-Latitude-3500:~/flutter_projects$ flutter upgrade
    Downloading Dart SDK from Flutter engine 99c2b3a2455511c3fd37521d9b00972c5345b75b...
      % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                     Dload  Upload   Total   Spent    Left  Speed
    100  253M  100  253M    0     0  3384k      0  0:01:16  0:01:16 --:--:-- 2883k
    Building flutter tool...
    Got socket error trying to find package args at https://pub.dartlang.org.
    Error: Unable to 'pub upgrade' flutter tool. Retrying in five seconds... (9 tries left)
    Flutter is already up to date on channel dev
    Flutter 1.21.0-1.0.pre • channel dev • https://github.com/flutter/flutter.git
    Framework • revision f25bd9c55c (6 days ago) • 2020-07-14 20:26:01 -0400
    Engine • revision 99c2b3a245
    Tools • Dart 2.9.0 (build 2.9.0-21.0.dev 20bf2fcf56)
    user@user-Latitude-3500:~/flutter_projects$
    user@user-Latitude-3500:~/flutter_projects$
    user@user-Latitude-3500:~/flutter_projects$
    user@user-Latitude-3500:~/flutter_projects$
    user@user-Latitude-3500:~/flutter_projects$ ping https://pub.dartlang.org
    ping: https://pub.dartlang.org: Name or service not known
    user@user-Latitude-3500:~/flutter_projects$
    user@user-Latitude-3500:~/flutter_projects$
    user@user-Latitude-3500:~/flutter_projects$
    user@user-Latitude-3500:~/flutter_projects$ ping pub.dartlang.org
    PING ghs.googlehosted.com (<IP_ADDRESS>) 56(84) bytes of data.
    64 bytes from pub.dartlang.org (<IP_ADDRESS>): icmp_seq=1 ttl=119 time=16.7 ms
    64 bytes from pub.dartlang.org (<IP_ADDRESS>): icmp_seq=2 ttl=119 time=19.7 ms
    64 bytes from pub.dartlang.org (<IP_ADDRESS>): icmp_seq=3 ttl=119 time=22.4 ms
    64 bytes from pub.dartlang.org (<IP_ADDRESS>): icmp_seq=4 ttl=119 time=22.8 ms
    64 bytes from pub.dartlang.org (<IP_ADDRESS>): icmp_seq=5 ttl=119 time=27.7 ms
    64 bytes from pub.dartlang.org (<IP_ADDRESS>): icmp_seq=6 ttl=119 time=20.8 ms
    64 bytes from pub.dartlang.org (<IP_ADDRESS>): icmp_seq=7 ttl=119 time=22.5 ms
    64 bytes from pub.dartlang.org (<IP_ADDRESS>): icmp_seq=8 ttl=119 time=23.9 ms
    64 bytes from pub.dartlang.org (<IP_ADDRESS>): icmp_seq=9 ttl=119 time=21.0 ms
    64 bytes from pub.dartlang.org (<IP_ADDRESS>): icmp_seq=10 ttl=119 time=21.9 ms
    64 bytes from pub.dartlang.org (<IP_ADDRESS>): icmp_seq=11 ttl=119 time=26.1 ms
    64 bytes from pub.dartlang.org (<IP_ADDRESS>): icmp_seq=12 ttl=119 time=22.3 ms
    64 bytes from pub.dartlang.org (<IP_ADDRESS>): icmp_seq=13 ttl=119 time=17.9 ms
    64 bytes from pub.dartlang.org (<IP_ADDRESS>): icmp_seq=14 ttl=119 time=26.0 ms
    64 bytes from pub.dartlang.org (<IP_ADDRESS>): icmp_seq=15 ttl=119 time=22.1 ms
    64 bytes from pub.dartlang.org (<IP_ADDRESS>): icmp_seq=16 ttl=119 time=18.9 ms
    64 bytes from pub.dartlang.org (<IP_ADDRESS>): icmp_seq=17 ttl=119 time=23.4 ms
    64 bytes from pub.dartlang.org (<IP_ADDRESS>): icmp_seq=18 ttl=119 time=32.8 ms
    64 bytes from pub.dartlang.org (<IP_ADDRESS>): icmp_seq=19 ttl=119 time=28.3 ms
    64 bytes from pub.dartlang.org (<IP_ADDRESS>): icmp_seq=20 ttl=119 time=29.5 ms
    64 bytes from pub.dartlang.org (<IP_ADDRESS>): icmp_seq=21 ttl=119 time=27.9 ms
    64 bytes from pub.dartlang.org (<IP_ADDRESS>): icmp_seq=22 ttl=119 time=34.5 ms
    64 bytes from pub.dartlang.org (<IP_ADDRESS>): icmp_seq=23 ttl=119 time=23.3 ms
    ^C
    --- ghs.googlehosted.com ping statistics ---
    23 packets transmitted, 23 received, 0% packet loss, time 22036ms
    rtt min/avg/max/mdev = 16.769/24.056/34.547/4.400 ms
    user@user-Latitude-3500:~/flutter_projects$
    user@user-Latitude-3500:~/flutter_projects$
    user@user-Latitude-3500:~/flutter_projects$
    user@user-Latitude-3500:~/flutter_projects$
    user@user-Latitude-3500:~/flutter_projects$
    user@user-Latitude-3500:~/flutter_projects$
    user@user-Latitude-3500:~/flutter_projects$ flutter doctor
    Downloading package sky_engine...                                   5.1s
    Downloading flutter_patched_sdk tools...                           28.0s
    Downloading flutter_patched_sdk_product tools...                   13.8s
    Downloading linux-x64 tools...                                     48.9s
    Downloading linux-x64/font-subset tools...                          6.5s
    Downloading android-arm-profile/linux-x64 tools...                  4.0s
    Downloading android-arm-release/linux-x64 tools...                  2.4s
    Downloading android-arm64-profile/linux-x64 tools...                2.0s
    Downloading android-arm64-release/linux-x64 tools...                7.8s
    Downloading android-x64-profile/linux-x64 tools...                  7.0s
    Downloading android-x64-release/linux-x64 tools...                  7.3s
    Doctor summary (to see all details, run flutter doctor -v):
    [✓] Flutter (Channel dev, 1.21.0-1.0.pre, on Linux, locale en_IN)
    [✓] Android toolchain - develop for Android devices (Android SDK version 30.0.1)
    [✓] Android Studio (version 4.0)
    [✓] VS Code (version 1.47.2)
    [!] Connected device
        ! No devices available

    ! Doctor found issues in 1 category.
    user@user-Latitude-3500:~/flutter_projects$
    user@user-Latitude-3500:~/flutter_projects$
    user@user-Latitude-3500:~/flutter_projects$
    user@user-Latitude-3500:~/flutter_projects$
    user@user-Latitude-3500:~/flutter_projects$
    user@user-Latitude-3500:~/flutter_projects$
        user@user-Latitude-3500:~/flutter_projects$
        user@user-Latitude-3500:~/flutter_projects$
        user@user-Latitude-3500:~/flutter_projects$ flutter create testapp_dev_2
        Creating project testapp_dev_2...
          testapp_dev_2/test/widget_test.dart (created)
          testapp_dev_2/.gitignore (created)
          testapp_dev_2/README.md (created)
          testapp_dev_2/android/app/src/debug/AndroidManifest.xml (created)
          testapp_dev_2/android/app/src/main/AndroidManifest.xml (created)
          testapp_dev_2/android/app/src/main/res/values/styles.xml (created)
          testapp_dev_2/android/app/src/main/res/drawable/launch_background.xml (created)
          testapp_dev_2/android/app/src/main/res/mipmap-xxhdpi/ic_launcher.png (created)
          testapp_dev_2/android/app/src/main/res/mipmap-mdpi/ic_launcher.png (created)
          testapp_dev_2/android/app/src/main/res/mipmap-hdpi/ic_launcher.png (created)
          testapp_dev_2/android/app/src/main/res/mipmap-xxxhdpi/ic_launcher.png (created)
          testapp_dev_2/android/app/src/main/res/mipmap-xhdpi/ic_launcher.png (created)
          testapp_dev_2/android/app/src/profile/AndroidManifest.xml (created)
          testapp_dev_2/android/gradle.properties (created)
          testapp_dev_2/android/settings.gradle (created)
          testapp_dev_2/android/.gitignore (created)
          testapp_dev_2/android/gradle/wrapper/gradle-wrapper.properties (created)
          testapp_dev_2/pubspec.yaml (created)
          testapp_dev_2/.idea/runConfigurations/main_dart.xml (created)
          testapp_dev_2/.idea/workspace.xml (created)
          testapp_dev_2/.idea/libraries/Dart_SDK.xml (created)
          testapp_dev_2/.idea/libraries/KotlinJavaRuntime.xml (created)
          testapp_dev_2/.idea/modules.xml (created)
          testapp_dev_2/ios/Runner.xcodeproj/xcshareddata/xcschemes/Runner.xcscheme (created)
          testapp_dev_2/ios/Runner.xcodeproj/project.xcworkspace/xcshareddata/WorkspaceSettings.xcsettings (created)
          testapp_dev_2/ios/Runner.xcodeproj/project.xcworkspace/xcshareddata/IDEWorkspaceChecks.plist (created)
          testapp_dev_2/ios/Runner.xcodeproj/project.xcworkspace/contents.xcworkspacedata (created)
          testapp_dev_2/ios/Flutter/Debug.xcconfig (created)
          testapp_dev_2/ios/Flutter/AppFrameworkInfo.plist (created)
          testapp_dev_2/ios/Flutter/Release.xcconfig (created)
          testapp_dev_2/ios/Runner.xcworkspace/xcshareddata/WorkspaceSettings.xcsettings (created)
          testapp_dev_2/ios/Runner.xcworkspace/xcshareddata/IDEWorkspaceChecks.plist (created)
          testapp_dev_2/ios/Runner.xcworkspace/contents.xcworkspacedata (created)
          testapp_dev_2/ios/.gitignore (created)
<EMAIL_ADDRESS>(created)
<EMAIL_ADDRESS>(created)
<EMAIL_ADDRESS>(created)
<EMAIL_ADDRESS>(created)
          testapp_dev_2/ios/Runner/Assets.xcassets/AppIcon.appiconset/Contents.json (created)
<EMAIL_ADDRESS>(created)
<EMAIL_ADDRESS>(created)
<EMAIL_ADDRESS>(created)
<EMAIL_ADDRESS>(created)
<EMAIL_ADDRESS>(created)
<EMAIL_ADDRESS>(created)
<EMAIL_ADDRESS>(created)
<EMAIL_ADDRESS>(created)
<EMAIL_ADDRESS>(created)
<EMAIL_ADDRESS>(created)
<EMAIL_ADDRESS>(created)
<EMAIL_ADDRESS>(created)
          testapp_dev_2/ios/Runner/Assets.xcassets/LaunchImage.imageset/Contents.json (created)
          testapp_dev_2/ios/Runner/Assets.xcassets/LaunchImage.imageset/LaunchImage.png (created)
          testapp_dev_2/ios/Runner/Assets.xcassets/LaunchImage.imageset/README.md (created)
<EMAIL_ADDRESS>(created)
          testapp_dev_2/ios/Runner/Base.lproj/Main.storyboard (created)
          testapp_dev_2/ios/Runner/Base.lproj/LaunchScreen.storyboard (created)
          testapp_dev_2/ios/Runner/Info.plist (created)
          testapp_dev_2/testapp_dev_2.iml (created)
          testapp_dev_2/lib/main.dart (created)
          testapp_dev_2/ios/Runner.xcodeproj/project.pbxproj (created)
          testapp_dev_2/ios/Runner/Runner-Bridging-Header.h (created)
          testapp_dev_2/ios/Runner/AppDelegate.swift (created)
          testapp_dev_2/.metadata (created)
          testapp_dev_2/android/app/build.gradle (created)
          testapp_dev_2/android/app/src/main/kotlin/com/example/testapp_dev_2/MainActivity.kt (created)
          testapp_dev_2/android/testapp_dev_2_android.iml (created)
          testapp_dev_2/android/build.gradle (created)
        Running "flutter pub get" in testapp_dev_2...                          ⣷^Cuser@user-Latitude-3500:~/flutter_projects$
        user@user-Latitude-3500:~/flutter_projects$
        user@user-Latitude-3500:~/flutter_projects$
        user@user-Latitude-3500:~/flutter_projects$
        user@user-Latitude-3500:~/flutter_projects$ ls
        iqc_dealer  testapp  testapp_dev  testapp_dev_2
        user@user-Latitude-3500:~/flutter_projects$
        user@user-Latitude-3500:~/flutter_projects$
        user@user-Latitude-3500:~/flutter_projects$
        user@user-Latitude-3500:~/flutter_projects$ flutter -v create testapp_dev_2
        [  +83 ms] executing: [/home/user/snap/flutter/common/flutter/] git -c log.showSignature=false log -n 1 --pretty=format:%H
        [  +20 ms] Exit code 0 from: git -c log.showSignature=false log -n 1 --pretty=format:%H
        [        ] f25bd9c55c48c139524139b477d04b13e9f36b2c
        [        ] executing: [/home/user/snap/flutter/common/flutter/] git tag --contains HEAD
        [ +139 ms] Exit code 0 from: git tag --contains HEAD
        [   +1 ms] 1.21.0-1.0.pre
        [   +6 ms] executing: [/home/user/snap/flutter/common/flutter/] git rev-parse --abbrev-ref --symbolic @{u}
        [   +3 ms] Exit code 0 from: git rev-parse --abbrev-ref --symbolic @{u}
        [        ] origin/dev
        [        ] executing: [/home/user/snap/flutter/common/flutter/] git ls-remote --get-url origin
        [   +3 ms] Exit code 0 from: git ls-remote --get-url origin
        [        ] https://github.com/flutter/flutter.git
        [  +36 ms] executing: [/home/user/snap/flutter/common/flutter/] git rev-parse --abbrev-ref HEAD
        [   +3 ms] Exit code 0 from: git rev-parse --abbrev-ref HEAD
        [        ] dev
        [  +34 ms] Artifact Instance of 'AndroidMavenArtifacts' is not required, skipping update.
        [        ] Artifact Instance of 'AndroidGenSnapshotArtifacts' is not required, skipping update.
        [        ] Artifact Instance of 'AndroidInternalBuildArtifacts' is not required, skipping update.
        [        ] Artifact Instance of 'IOSEngineArtifacts' is not required, skipping update.
        [        ] Artifact Instance of 'FlutterWebSdk' is not required, skipping update.
        [   +1 ms] Artifact Instance of 'WindowsEngineArtifacts' is not required, skipping update.
        [        ] Artifact Instance of 'MacOSEngineArtifacts' is not required, skipping update.
        [        ] Artifact Instance of 'LinuxEngineArtifacts' is not required, skipping update.
        [        ] Artifact Instance of 'LinuxFuchsiaSDKArtifacts' is not required, skipping update.
        [        ] Artifact Instance of 'MacOSFuchsiaSDKArtifacts' is not required, skipping update.
        [        ] Artifact Instance of 'FlutterRunnerSDKArtifacts' is not required, skipping update.
        [        ] Artifact Instance of 'FlutterRunnerDebugSymbols' is not required, skipping update.
        [   +5 ms] Artifact Instance of 'MaterialFonts' is not required, skipping update.
        [        ] Artifact Instance of 'GradleWrapper' is not required, skipping update.
        [        ] Artifact Instance of 'AndroidMavenArtifacts' is not required, skipping update.
        [        ] Artifact Instance of 'AndroidGenSnapshotArtifacts' is not required, skipping update.
        [        ] Artifact Instance of 'AndroidInternalBuildArtifacts' is not required, skipping update.
        [        ] Artifact Instance of 'IOSEngineArtifacts' is not required, skipping update.
        [        ] Artifact Instance of 'FlutterWebSdk' is not required, skipping update.
        [        ] Artifact Instance of 'FlutterSdk' is not required, skipping update.
        [        ] Artifact Instance of 'WindowsEngineArtifacts' is not required, skipping update.
        [        ] Artifact Instance of 'MacOSEngineArtifacts' is not required, skipping update.
        [        ] Artifact Instance of 'LinuxEngineArtifacts' is not required, skipping update.
        [        ] Artifact Instance of 'LinuxFuchsiaSDKArtifacts' is not required, skipping update.
        [        ] Artifact Instance of 'MacOSFuchsiaSDKArtifacts' is not required, skipping update.
        [        ] Artifact Instance of 'FlutterRunnerSDKArtifacts' is not required, skipping update.
        [        ] Artifact Instance of 'FlutterRunnerDebugSymbols' is not required, skipping update.
        [        ] Artifact Instance of 'IosUsbArtifacts' is not required, skipping update.
        [        ] Artifact Instance of 'IosUsbArtifacts' is not required, skipping update.
        [        ] Artifact Instance of 'IosUsbArtifacts' is not required, skipping update.
        [        ] Artifact Instance of 'IosUsbArtifacts' is not required, skipping update.
        [        ] Artifact Instance of 'IosUsbArtifacts' is not required, skipping update.
        [        ] Artifact Instance of 'FontSubsetArtifacts' is not required, skipping update.
        [  +86 ms] Recreating project testapp_dev_2...
        [  +55 ms]   testapp_dev_2/test/widget_test.dart (existing - skipped)
        [        ]   testapp_dev_2/.gitignore (existing - skipped)
        [        ]   testapp_dev_2/README.md (existing - skipped)
        [        ]   testapp_dev_2/android/app/src/debug/AndroidManifest.xml (existing - skipped)
        [        ]   testapp_dev_2/android/app/src/main/AndroidManifest.xml (existing - skipped)
        [        ]   testapp_dev_2/android/app/src/main/res/values/styles.xml (existing - skipped)
        [        ]   testapp_dev_2/android/app/src/main/res/drawable/launch_background.xml (existing - skipped)
        [        ]   testapp_dev_2/android/app/src/main/res/mipmap-xxhdpi/ic_launcher.png (existing - skipped)
        [        ]   testapp_dev_2/android/app/src/main/res/mipmap-mdpi/ic_launcher.png (existing - skipped)
        [        ]   testapp_dev_2/android/app/src/main/res/mipmap-hdpi/ic_launcher.png (existing - skipped)
        [        ]   testapp_dev_2/android/app/src/main/res/mipmap-xxxhdpi/ic_launcher.png (existing - skipped)
        [        ]   testapp_dev_2/android/app/src/main/res/mipmap-xhdpi/ic_launcher.png (existing - skipped)
        [        ]   testapp_dev_2/android/app/src/profile/AndroidManifest.xml (existing - skipped)
        [        ]   testapp_dev_2/android/gradle.properties (existing - skipped)
        [        ]   testapp_dev_2/android/settings.gradle (existing - skipped)
        [        ]   testapp_dev_2/android/.gitignore (existing - skipped)
        [        ]   testapp_dev_2/android/gradle/wrapper/gradle-wrapper.properties (existing - skipped)
        [        ]   testapp_dev_2/pubspec.yaml (existing - skipped)
        [        ]   testapp_dev_2/.idea/runConfigurations/main_dart.xml (existing - skipped)
        [        ]   testapp_dev_2/.idea/workspace.xml (existing - skipped)
        [        ]   testapp_dev_2/.idea/libraries/Dart_SDK.xml (existing - skipped)
        [        ]   testapp_dev_2/.idea/libraries/KotlinJavaRuntime.xml (existing - skipped)
        [        ]   testapp_dev_2/.idea/modules.xml (existing - skipped)
        [        ]   testapp_dev_2/ios/Runner.xcodeproj/xcshareddata/xcschemes/Runner.xcscheme (existing - skipped)
        [        ]   testapp_dev_2/ios/Runner.xcodeproj/project.xcworkspace/xcshareddata/WorkspaceSettings.xcsettings (existing - skipped)
        [        ]   testapp_dev_2/ios/Runner.xcodeproj/project.xcworkspace/xcshareddata/IDEWorkspaceChecks.plist (existing - skipped)
        [        ]   testapp_dev_2/ios/Runner.xcodeproj/project.xcworkspace/contents.xcworkspacedata (existing - skipped)
        [        ]   testapp_dev_2/ios/Flutter/Debug.xcconfig (existing - skipped)
        [        ]   testapp_dev_2/ios/Flutter/AppFrameworkInfo.plist (existing - skipped)
        [        ]   testapp_dev_2/ios/Flutter/Release.xcconfig (existing - skipped)
        [        ]   testapp_dev_2/ios/Runner.xcworkspace/xcshareddata/WorkspaceSettings.xcsettings (existing - skipped)
        [        ]   testapp_dev_2/ios/Runner.xcworkspace/xcshareddata/IDEWorkspaceChecks.plist (existing - skipped)
        [        ]   testapp_dev_2/ios/Runner.xcworkspace/contents.xcworkspacedata (existing - skipped)
        [        ]   testapp_dev_2/ios/.gitignore (existing - skipped)
        [        ]<EMAIL_ADDRESS>(existing - skipped)
        [        ]<EMAIL_ADDRESS>(existing - skipped)
        [        ]<EMAIL_ADDRESS>(existing - skipped)
        [        ]<EMAIL_ADDRESS>(existing - skipped)
        [        ]   testapp_dev_2/ios/Runner/Assets.xcassets/AppIcon.appiconset/Contents.json (existing - skipped)
        [        ]<EMAIL_ADDRESS>(existing - skipped)
        [        ]<EMAIL_ADDRESS>(existing - skipped)
        [        ]<EMAIL_ADDRESS>(existing - skipped)
        [        ]<EMAIL_ADDRESS>(existing - skipped)
        [        ]<EMAIL_ADDRESS>(existing - skipped)
        [        ]<EMAIL_ADDRESS>(existing - skipped)
        [        ]<EMAIL_ADDRESS>(existing - skipped)
        [   +2 ms]<EMAIL_ADDRESS>(existing - skipped)
        [        ]<EMAIL_ADDRESS>(existing - skipped)
        [        ]<EMAIL_ADDRESS>(existing - skipped)
        [        ]<EMAIL_ADDRESS>(existing - skipped)
        [        ]<EMAIL_ADDRESS>(existing - skipped)
        [        ]   testapp_dev_2/ios/Runner/Assets.xcassets/LaunchImage.imageset/Contents.json (existing - skipped)
        [        ]   testapp_dev_2/ios/Runner/Assets.xcassets/LaunchImage.imageset/LaunchImage.png (existing - skipped)
        [        ]   testapp_dev_2/ios/Runner/Assets.xcassets/LaunchImage.imageset/README.md (existing - skipped)
        [        ]<EMAIL_ADDRESS>(existing - skipped)
        [        ]   testapp_dev_2/ios/Runner/Base.lproj/Main.storyboard (existing - skipped)
        [        ]   testapp_dev_2/ios/Runner/Base.lproj/LaunchScreen.storyboard (existing - skipped)
        [        ]   testapp_dev_2/ios/Runner/Info.plist (existing - skipped)
        [        ]   testapp_dev_2/testapp_dev_2.iml (existing - skipped)
        [        ]   testapp_dev_2/lib/main.dart (existing - skipped)
        [        ]   testapp_dev_2/ios/Runner.xcodeproj/xcshareddata/xcschemes/Runner.xcscheme (existing - skipped)
        [        ]   testapp_dev_2/ios/Runner.xcodeproj/project.pbxproj (existing - skipped)
        [        ]   testapp_dev_2/ios/Runner/Runner-Bridging-Header.h (existing - skipped)
        [        ]   testapp_dev_2/ios/Runner/AppDelegate.swift (existing - skipped)
        [        ]   testapp_dev_2/.metadata (existing - skipped)
        [        ]   testapp_dev_2/android/app/build.gradle (existing - skipped)
        [        ]   testapp_dev_2/android/app/src/main/kotlin/com/example/testapp_dev_2/MainActivity.kt (existing - skipped)
        [        ]   testapp_dev_2/android/testapp_dev_2_android.iml (existing - skipped)
        [        ]   testapp_dev_2/android/build.gradle (existing - skipped)
        [  +10 ms] Running "flutter pub get" in testapp_dev_2...
        [   +2 ms] Using /home/user/snap/flutter/common/flutter/.pub-cache for the pub cache.
        [        ] executing: [/home/user/flutter_projects/testapp_dev_2/] /home/user/snap/flutter/common/flutter/bin/cache/dart-sdk/bin/pub --verbose get
        --no-precompile
        [  +52 ms] FINE: Pub 2.9.0-21.0.dev.flutter-20bf2fcf56
        [  +48 ms] MSG : Resolving dependencies...
        [  +10 ms] SLVR: fact: testapp_dev_2 is 1.0.0+1
        [   +5 ms] SLVR: derived: testapp_dev_2
        [  +22 ms] SLVR: fact: testapp_dev_2 depends on flutter any from sdk
        [        ] SLVR: fact: testapp_dev_2 depends on cupertino_icons ^0.1.3
        [        ] SLVR: fact: testapp_dev_2 depends on flutter_test any from sdk
        [        ] SLVR:   selecting testapp_dev_2
        [        ] SLVR:   derived: flutter_test any from sdk
        [        ] SLVR:   derived: cupertino_icons ^0.1.3
        [        ] SLVR:   derived: flutter any from sdk
        [  +22 ms] IO  : Get versions from https://pub.dartlang.org/api/packages/cupertino_icons.
        [  +16 ms] IO  : HTTP GET https://pub.dartlang.org/api/packages/cupertino_icons
        [        ]     | Accept: application/vnd.pub.v2+json
        [        ]     | X-Pub-OS: linux
        [        ]     | X-Pub-Command: get
        [        ]     | X-Pub-Session-ID: 384FBBC4-7A95-492D-902E-0A79955CDCF0
        [        ]     | X-Pub-Environment: flutter_cli:create
        [        ]     | X-Pub-Reason: direct
        [        ]     | user-agent: Dart pub 2.9.0-21.0.dev.flutter-20bf2fcf56

Hi @nvmav
is being behind a firewall your case?
does it work if you set mirror sites https://flutter.dev/community/china#configuring-flutter-to-use-a-mirror-site?

@VladyslavBondarenko
No. There was no firewall, no proxy or any kind of network restriction. I was using Wi-Fi network at home in India.
I haven't tried setting any mirror site.
I shut down my laptop yesterday night and today morning when I tried to create, it worked. I am not sure why.
You can close this issue for now. Next time if it occurs again, I will try mirror sites. Even after that, if it is NOT working, I will re-open this issue.
Verbose log when creation was success:
user@user-Latitude-3500:~/flutter_projects$
  user@user-Latitude-3500:~/flutter_projects$
  user@user-Latitude-3500:~/flutter_projects$
  user@user-Latitude-3500:~/flutter_projects$ flutter -v create testapp_dev_boot_1
  [ +183 ms] executing: [/home/user/snap/flutter/common/flutter/] git -c log.showSignature=false log -n 1 --pretty=format:%H
  [  +41 ms] Exit code 0 from: git -c log.showSignature=false log -n 1 --pretty=format:%H
  [        ] f25bd9c55c48c139524139b477d04b13e9f36b2c
  [        ] executing: [/home/user/snap/flutter/common/flutter/] git tag --contains HEAD
  [ +273 ms] Exit code 0 from: git tag --contains HEAD
  [        ] 1.21.0-1.0.pre
  [  +14 ms] executing: [/home/user/snap/flutter/common/flutter/] git rev-parse --abbrev-ref --symbolic @{u}
  [   +6 ms] Exit code 0 from: git rev-parse --abbrev-ref --symbolic @{u}
  [        ] origin/dev
  [        ] executing: [/home/user/snap/flutter/common/flutter/] git ls-remote --get-url origin
  [   +5 ms] Exit code 0 from: git ls-remote --get-url origin
  [        ] https://github.com/flutter/flutter.git
  [  +66 ms] executing: [/home/user/snap/flutter/common/flutter/] git rev-parse --abbrev-ref HEAD
  [   +6 ms] Exit code 0 from: git rev-parse --abbrev-ref HEAD
  [        ] dev
  [  +66 ms] Artifact Instance of 'AndroidMavenArtifacts' is not required, skipping update.
  [        ] Artifact Instance of 'AndroidGenSnapshotArtifacts' is not required, skipping update.
  [        ] Artifact Instance of 'AndroidInternalBuildArtifacts' is not required, skipping update.
  [        ] Artifact Instance of 'IOSEngineArtifacts' is not required, skipping update.
  [        ] Artifact Instance of 'FlutterWebSdk' is not required, skipping update.
  [   +3 ms] Artifact Instance of 'WindowsEngineArtifacts' is not required, skipping update.
  [        ] Artifact Instance of 'MacOSEngineArtifacts' is not required, skipping update.
  [        ] Artifact Instance of 'LinuxEngineArtifacts' is not required, skipping update.
  [        ] Artifact Instance of 'LinuxFuchsiaSDKArtifacts' is not required, skipping update.
  [        ] Artifact Instance of 'MacOSFuchsiaSDKArtifacts' is not required, skipping update.
  [        ] Artifact Instance of 'FlutterRunnerSDKArtifacts' is not required, skipping update.
  [        ] Artifact Instance of 'FlutterRunnerDebugSymbols' is not required, skipping update.
  [  +17 ms] Artifact Instance of 'MaterialFonts' is not required, skipping update.
  [        ] Artifact Instance of 'GradleWrapper' is not required, skipping update.
  [        ] Artifact Instance of 'AndroidMavenArtifacts' is not required, skipping update.
  [        ] Artifact Instance of 'AndroidGenSnapshotArtifacts' is not required, skipping update.
  [        ] Artifact Instance of 'AndroidInternalBuildArtifacts' is not required, skipping update.
  [        ] Artifact Instance of 'IOSEngineArtifacts' is not required, skipping update.
  [        ] Artifact Instance of 'FlutterWebSdk' is not required, skipping update.
  [        ] Artifact Instance of 'FlutterSdk' is not required, skipping update.
  [        ] Artifact Instance of 'WindowsEngineArtifacts' is not required, skipping update.
  [        ] Artifact Instance of 'MacOSEngineArtifacts' is not required, skipping update.
  [        ] Artifact Instance of 'LinuxEngineArtifacts' is not required, skipping update.
  [        ] Artifact Instance of 'LinuxFuchsiaSDKArtifacts' is not required, skipping update.
  [        ] Artifact Instance of 'MacOSFuchsiaSDKArtifacts' is not required, skipping update.
  [        ] Artifact Instance of 'FlutterRunnerSDKArtifacts' is not required, skipping update.
  [        ] Artifact Instance of 'FlutterRunnerDebugSymbols' is not required, skipping update.
  [        ] Artifact Instance of 'IosUsbArtifacts' is not required, skipping update.
  [        ] Artifact Instance of 'IosUsbArtifacts' is not required, skipping update.
  [        ] Artifact Instance of 'IosUsbArtifacts' is not required, skipping update.
  [        ] Artifact Instance of 'IosUsbArtifacts' is not required, skipping update.
  [        ] Artifact Instance of 'IosUsbArtifacts' is not required, skipping update.
  [        ] Artifact Instance of 'FontSubsetArtifacts' is not required, skipping update.
  [  +93 ms] Creating project testapp_dev_boot_1...
  [ +110 ms]   testapp_dev_boot_1/test/widget_test.dart (created)
  [  +24 ms]   testapp_dev_boot_1/.gitignore (created)
  [   +1 ms]   testapp_dev_boot_1/README.md (created)
  [   +1 ms]   testapp_dev_boot_1/android/app/src/debug/AndroidManifest.xml (created)
  [   +1 ms]   testapp_dev_boot_1/android/app/src/main/AndroidManifest.xml (created)
  [   +2 ms]   testapp_dev_boot_1/android/app/src/main/res/values/styles.xml (created)
  [   +4 ms]   testapp_dev_boot_1/android/app/src/main/res/drawable/launch_background.xml (created)
  [   +1 ms]   testapp_dev_boot_1/android/app/src/main/res/mipmap-xxhdpi/ic_launcher.png (created)
  [        ]   testapp_dev_boot_1/android/app/src/main/res/mipmap-mdpi/ic_launcher.png (created)
  [        ]   testapp_dev_boot_1/android/app/src/main/res/mipmap-hdpi/ic_launcher.png (created)
  [        ]   testapp_dev_boot_1/android/app/src/main/res/mipmap-xxxhdpi/ic_launcher.png (created)
  [        ]   testapp_dev_boot_1/android/app/src/main/res/mipmap-xhdpi/ic_launcher.png (created)
  [        ]   testapp_dev_boot_1/android/app/src/profile/AndroidManifest.xml (created)
  [   +1 ms]   testapp_dev_boot_1/android/gradle.properties (created)
  [        ]   testapp_dev_boot_1/android/settings.gradle (created)
  [        ]   testapp_dev_boot_1/android/.gitignore (created)
  [        ]   testapp_dev_boot_1/android/gradle/wrapper/gradle-wrapper.properties (created)
  [        ]   testapp_dev_boot_1/pubspec.yaml (created)
  [   +4 ms]   testapp_dev_boot_1/.idea/runConfigurations/main_dart.xml (created)
  [   +2 ms]   testapp_dev_boot_1/.idea/workspace.xml (created)
  [   +3 ms]   testapp_dev_boot_1/.idea/libraries/Dart_SDK.xml (created)
  [   +1 ms]   testapp_dev_boot_1/.idea/libraries/KotlinJavaRuntime.xml (created)
  [   +1 ms]   testapp_dev_boot_1/.idea/modules.xml (created)
  [   +1 ms]   testapp_dev_boot_1/ios/Runner.xcodeproj/xcshareddata/xcschemes/Runner.xcscheme (created)
  [   +1 ms]   testapp_dev_boot_1/ios/Runner.xcodeproj/project.xcworkspace/xcshareddata/WorkspaceSettings.xcsettings (created)
  [   +1 ms]   testapp_dev_boot_1/ios/Runner.xcodeproj/project.xcworkspace/xcshareddata/IDEWorkspaceChecks.plist (created)
  [        ]   testapp_dev_boot_1/ios/Runner.xcodeproj/project.xcworkspace/contents.xcworkspacedata (created)
  [        ]   testapp_dev_boot_1/ios/Flutter/Debug.xcconfig (created)
  [        ]   testapp_dev_boot_1/ios/Flutter/AppFrameworkInfo.plist (created)
  [        ]   testapp_dev_boot_1/ios/Flutter/Release.xcconfig (created)
  [        ]   testapp_dev_boot_1/ios/Runner.xcworkspace/xcshareddata/WorkspaceSettings.xcsettings (created)
  [        ]   testapp_dev_boot_1/ios/Runner.xcworkspace/xcshareddata/IDEWorkspaceChecks.plist (created)
  [        ]   testapp_dev_boot_1/ios/Runner.xcworkspace/contents.xcworkspacedata (created)
  [        ]   testapp_dev_boot_1/ios/.gitignore (created)
  [        ]<EMAIL_ADDRESS>(created)
  [        ]<EMAIL_ADDRESS>(created)
  [        ]<EMAIL_ADDRESS>(created)
  [        ]<EMAIL_ADDRESS>(created)
  [        ]   testapp_dev_boot_1/ios/Runner/Assets.xcassets/AppIcon.appiconset/Contents.json (created)
  [        ]<EMAIL_ADDRESS>(created)
  [        ]<EMAIL_ADDRESS>(created)
  [        ]<EMAIL_ADDRESS>(created)
  [        ]<EMAIL_ADDRESS>(created)
  [        ]<EMAIL_ADDRESS>(created)
  [        ]<EMAIL_ADDRESS>(created)
  [        ]<EMAIL_ADDRESS>(created)
  [        ]<EMAIL_ADDRESS>(created)
  [        ]<EMAIL_ADDRESS>(created)
  [        ]<EMAIL_ADDRESS>(created)
  [        ]<EMAIL_ADDRESS>(created)
  [        ]<EMAIL_ADDRESS>(created)
  [        ]   testapp_dev_boot_1/ios/Runner/Assets.xcassets/LaunchImage.imageset/Contents.json (created)
  [        ]   testapp_dev_boot_1/ios/Runner/Assets.xcassets/LaunchImage.imageset/LaunchImage.png (created)
  [        ]   testapp_dev_boot_1/ios/Runner/Assets.xcassets/LaunchImage.imageset/README.md (created)
  [        ]<EMAIL_ADDRESS>(created)
  [        ]   testapp_dev_boot_1/ios/Runner/Base.lproj/Main.storyboard (created)
  [        ]   testapp_dev_boot_1/ios/Runner/Base.lproj/LaunchScreen.storyboard (created)
  [        ]   testapp_dev_boot_1/ios/Runner/Info.plist (created)
  [   +3 ms]   testapp_dev_boot_1/testapp_dev_boot_1.iml (created)
  [   +1 ms]   testapp_dev_boot_1/lib/main.dart (created)
  [   +2 ms]   testapp_dev_boot_1/ios/Runner.xcodeproj/xcshareddata/xcschemes/Runner.xcscheme (existing - skipped)
  [        ]   testapp_dev_boot_1/ios/Runner.xcodeproj/project.pbxproj (created)
  [   +6 ms]   testapp_dev_boot_1/ios/Runner/Runner-Bridging-Header.h (created)
  [        ]   testapp_dev_boot_1/ios/Runner/AppDelegate.swift (created)
  [        ]   testapp_dev_boot_1/.metadata (created)
  [        ]   testapp_dev_boot_1/android/app/build.gradle (created)
  [  +49 ms]   testapp_dev_boot_1/android/app/src/main/kotlin/com/example/testapp_dev_boot_1/MainActivity.kt (created)
  [  +32 ms]   testapp_dev_boot_1/android/testapp_dev_boot_1_android.iml (created)
  [  +11 ms]   testapp_dev_boot_1/android/build.gradle (created)
  [ +158 ms] Running "flutter pub get" in testapp_dev_boot_1...
  [   +5 ms] Using /home/user/snap/flutter/common/flutter/.pub-cache for the pub cache.
  [   +1 ms] executing: [/home/user/flutter_projects/testapp_dev_boot_1/] /home/user/snap/flutter/common/flutter/bin/cache/dart-sdk/bin/pub
  --verbose get --no-precompile
  [  +87 ms] FINE: Pub 2.9.0-21.0.dev.flutter-20bf2fcf56
  [  +76 ms] MSG : Resolving dependencies...
  [  +20 ms] SLVR: fact: testapp_dev_boot_1 is 1.0.0+1
  [   +8 ms] SLVR: derived: testapp_dev_boot_1
  [  +44 ms] SLVR: fact: testapp_dev_boot_1 depends on flutter any from sdk
  [        ] SLVR: fact: testapp_dev_boot_1 depends on cupertino_icons ^0.1.3
  [        ] SLVR: fact: testapp_dev_boot_1 depends on flutter_test any from sdk
  [   +1 ms] SLVR:   selecting testapp_dev_boot_1
  [        ] SLVR:   derived: flutter_test any from sdk
  [        ] SLVR:   derived: cupertino_icons ^0.1.3
  [        ] SLVR:   derived: flutter any from sdk
  [  +38 ms] IO  : Get versions from https://pub.dartlang.org/api/packages/cupertino_icons.
  [  +33 ms] IO  : HTTP GET https://pub.dartlang.org/api/packages/cupertino_icons
  [        ]     | Accept: application/vnd.pub.v2+json
  [        ]     | X-Pub-OS: linux
  [        ]     | X-Pub-Command: get
  [        ]     | X-Pub-Session-ID: E0E7DEC7-525C-44A8-91DC-5A6CDBA160F6
  [        ]     | X-Pub-Environment: flutter_cli:create
  [        ]     | X-Pub-Reason: direct
  [        ]     | user-agent: Dart pub 2.9.0-21.0.dev.flutter-20bf2fcf56
  [+1409 ms] IO  : HTTP response 200 OK for GET https://pub.dartlang.org/api/packages/cupertino_icons
  [        ]     | took 0:00:01.409738
  [        ]     | transfer-encoding: chunked
  [        ]     | date: Tue, 21 Jul 2020 11:57:37 GMT
  [        ]     | content-encoding: gzip
  [        ]     | vary: Accept-Encoding
  [        ]     | strict-transport-security: max-age=31536000; preload
  [        ]     | via: 1.1 google
  [        ]     | content-type: application/json; charset="utf-8"
  [        ]     | x-frame-options: SAMEORIGIN
  [        ]     | x-xss-protection: 1; mode=block
  [        ]     | x-content-type-options: nosniff
  [        ]     | server: dart:io with Shelf
  [ +105 ms] SLVR:   fact: every version of flutter_test from sdk depends on async 2.4.2
  [        ] SLVR:   fact: every version of flutter_test from sdk depends on boolean_selector 2.0.0
  [        ] SLVR:   fact: every version of flutter_test from sdk depends on characters 1.1.0-nullsafety
  [        ] SLVR:   fact: every version of flutter_test from sdk depends on charcode 1.1.3
  [        ] SLVR:   fact: every version of flutter_test from sdk depends on clock 1.0.1
  [        ] SLVR:   fact: every version of flutter_test from sdk depends on collection 1.15.0-nullsafety
  [        ] SLVR:   fact: every version of flutter_test from sdk depends on fake_async 1.1.0
  [        ] SLVR:   fact: every version of flutter_test from sdk depends on flutter any from sdk
  [        ] SLVR:   fact: every version of flutter_test from sdk depends on matcher 0.12.8
  [        ] SLVR:   fact: every version of flutter_test from sdk depends on meta 1.3.0-nullsafety
  [        ] SLVR:   fact: every version of flutter_test from sdk depends on path 1.7.0
  [        ] SLVR:   fact: every version of flutter_test from sdk depends on source_span 1.7.0
  [        ] SLVR:   fact: every version of flutter_test from sdk depends on stack_trace 1.9.5
  [        ] SLVR:   fact: every version of flutter_test from sdk depends on stream_channel 2.0.0
  [        ] SLVR:   fact: every version of flutter_test from sdk depends on string_scanner 1.0.5
  [        ] SLVR:   fact: every version of flutter_test from sdk depends on term_glyph 1.1.0
  [        ] SLVR:   fact: every version of flutter_test from sdk depends on test_api 0.2.17
  [        ] SLVR:   fact: every version of flutter_test from sdk depends on typed_data 1.3.0-nullsafety
  [        ] SLVR:   fact: every version of flutter_test from sdk depends on vector_math 2.1.0-nullsafety
  [        ] SLVR:     selecting flutter_test 0.0.0 from sdk
  [        ] SLVR:     derived: vector_math 2.1.0-nullsafety
  [        ] SLVR:     derived: typed_data 1.3.0-nullsafety
  [        ] SLVR:     derived: test_api 0.2.17
  [        ] SLVR:     derived: term_glyph 1.1.0
  [        ] SLVR:     derived: string_scanner 1.0.5
  [        ] SLVR:     derived: stream_channel 2.0.0
  [        ] SLVR:     derived: stack_trace 1.9.5
  [        ] SLVR:     derived: source_span 1.7.0
  [        ] SLVR:     derived: path 1.7.0
  [        ] SLVR:     derived: meta 1.3.0-nullsafety
  [        ] SLVR:     derived: matcher 0.12.8
  [        ] SLVR:     derived: fake_async 1.1.0
  [        ] SLVR:     derived: collection 1.15.0-nullsafety
  [        ] SLVR:     derived: clock 1.0.1
  [        ] SLVR:     derived: charcode 1.1.3
  [        ] SLVR:     derived: characters 1.1.0-nullsafety
  [        ] SLVR:     derived: boolean_selector 2.0.0
  [        ] SLVR:     derived: async 2.4.2
  [   +7 ms] IO  : Get versions from https://pub.dartlang.org/api/packages/async.
  [        ] IO  : Get versions from https://pub.dartlang.org/api/packages/boolean_selector.
  [        ] IO  : Get versions from https://pub.dartlang.org/api/packages/characters.
  [        ] IO  : Get versions from https://pub.dartlang.org/api/packages/charcode.
  [        ] IO  : Get versions from https://pub.dartlang.org/api/packages/clock.
  [        ] IO  : Get versions from https://pub.dartlang.org/api/packages/collection.
  [        ] IO  : Get versions from https://pub.dartlang.org/api/packages/fake_async.
  [        ] IO  : Get versions from https://pub.dartlang.org/api/packages/matcher.
  [        ] IO  : Get versions from https://pub.dartlang.org/api/packages/meta.
  [        ] IO  : Get versions from https://pub.dartlang.org/api/packages/path.
  [        ] IO  : HTTP GET https://pub.dartlang.org/api/packages/async
  [        ]     | Accept: application/vnd.pub.v2+json
  [        ]     | X-Pub-OS: linux
  [        ]     | X-Pub-Command: get
  [        ]     | X-Pub-Session-ID: E0E7DEC7-525C-44A8-91DC-5A6CDBA160F6
  [        ]     | X-Pub-Environment: flutter_cli:create
  [        ]     | user-agent: Dart pub 2.9.0-21.0.dev.flutter-20bf2fcf56
  [        ] IO  : HTTP GET https://pub.dartlang.org/api/packages/boolean_selector
  [        ]     | Accept: application/vnd.pub.v2+json
  [        ]     | X-Pub-OS: linux
  [        ]     | X-Pub-Command: get
  [        ]     | X-Pub-Session-ID: E0E7DEC7-525C-44A8-91DC-5A6CDBA160F6
  [        ]     | X-Pub-Environment: flutter_cli:create
  [        ]     | user-agent: Dart pub 2.9.0-21.0.dev.flutter-20bf2fcf56
  [        ] IO  : HTTP GET https://pub.dartlang.org/api/packages/characters
  [        ]     | Accept: application/vnd.pub.v2+json
  [        ]     | X-Pub-OS: linux
  [        ]     | X-Pub-Command: get
  [        ]     | X-Pub-Session-ID: E0E7DEC7-525C-44A8-91DC-5A6CDBA160F6
  [        ]     | X-Pub-Environment: flutter_cli:create
  [        ]     | user-agent: Dart pub 2.9.0-21.0.dev.flutter-20bf2fcf56
  [        ] IO  : HTTP GET https://pub.dartlang.org/api/packages/charcode
  [        ]     | Accept: application/vnd.pub.v2+json
  [        ]     | X-Pub-OS: linux
  [        ]     | X-Pub-Command: get
  [        ]     | X-Pub-Session-ID: E0E7DEC7-525C-44A8-91DC-5A6CDBA160F6
  [        ]     | X-Pub-Environment: flutter_cli:create
  [        ]     | user-agent: Dart pub 2.9.0-21.0.dev.flutter-20bf2fcf56
  [        ] IO  : HTTP GET https://pub.dartlang.org/api/packages/clock
  [        ]     | Accept: application/vnd.pub.v2+json
  [        ]     | X-Pub-OS: linux
  [        ]     | X-Pub-Command: get
  [        ]     | X-Pub-Session-ID: E0E7DEC7-525C-44A8-91DC-5A6CDBA160F6
  [        ]     | X-Pub-Environment: flutter_cli:create
  [        ]     | user-agent: Dart pub 2.9.0-21.0.dev.flutter-20bf2fcf56
  [        ] IO  : HTTP GET https://pub.dartlang.org/api/packages/collection
  [        ]     | Accept: application/vnd.pub.v2+json
  [        ]     | X-Pub-OS: linux
  [        ]     | X-Pub-Command: get
  [        ]     | X-Pub-Session-ID: E0E7DEC7-525C-44A8-91DC-5A6CDBA160F6
  [        ]     | X-Pub-Environment: flutter_cli:create
  [        ]     | user-agent: Dart pub 2.9.0-21.0.dev.flutter-20bf2fcf56
  [        ] IO  : HTTP GET https://pub.dartlang.org/api/packages/fake_async
  [        ]     | Accept: application/vnd.pub.v2+json
  [        ]     | X-Pub-OS: linux
  [        ]     | X-Pub-Command: get
  [        ]     | X-Pub-Session-ID: E0E7DEC7-525C-44A8-91DC-5A6CDBA160F6
  [        ]     | X-Pub-Environment: flutter_cli:create
  [        ]     | user-agent: Dart pub 2.9.0-21.0.dev.flutter-20bf2fcf56
  [        ] IO  : HTTP GET https://pub.dartlang.org/api/packages/matcher
  [        ]     | Accept: application/vnd.pub.v2+json
  [        ]     | X-Pub-OS: linux
  [        ]     | X-Pub-Command: get
  [        ]     | X-Pub-Session-ID: E0E7DEC7-525C-44A8-91DC-5A6CDBA160F6
  [        ]     | X-Pub-Environment: flutter_cli:create
  [        ]     | user-agent: Dart pub 2.9.0-21.0.dev.flutter-20bf2fcf56
  [        ] IO  : HTTP GET https://pub.dartlang.org/api/packages/meta
  [        ]     | Accept: application/vnd.pub.v2+json
  [        ]     | X-Pub-OS: linux
  [        ]     | X-Pub-Command: get
  [        ]     | X-Pub-Session-ID: E0E7DEC7-525C-44A8-91DC-5A6CDBA160F6
  [        ]     | X-Pub-Environment: flutter_cli:create
  [        ]     | user-agent: Dart pub 2.9.0-21.0.dev.flutter-20bf2fcf56
  [        ] IO  : HTTP GET https://pub.dartlang.org/api/packages/path
  [        ]     | Accept: application/vnd.pub.v2+json
  [        ]     | X-Pub-OS: linux
  [        ]     | X-Pub-Command: get
  [        ]     | X-Pub-Session-ID: E0E7DEC7-525C-44A8-91DC-5A6CDBA160F6
  [        ]     | X-Pub-Environment: flutter_cli:create
  [        ]     | user-agent: Dart pub 2.9.0-21.0.dev.flutter-20bf2fcf56
  [ +379 ms] IO  : HTTP response 200 OK for GET https://pub.dartlang.org/api/packages/async
  [        ]     | took 0:00:00.399573
  [        ]     | transfer-encoding: chunked
  [        ]     | date: Tue, 21 Jul 2020 11:57:37 GMT
  [        ]     | content-encoding: gzip
  [        ]     | vary: Accept-Encoding
  [        ]     | strict-transport-security: max-age=31536000; preload
  [        ]     | via: 1.1 google
  [        ]     | content-type: application/json; charset="utf-8"
  [        ]     | x-frame-options: SAMEORIGIN
  [        ]     | x-xss-protection: 1; mode=block
  [        ]     | x-content-type-options: nosniff
  [        ]     | server: dart:io with Shelf
  [  +47 ms] IO  : Get versions from https://pub.dartlang.org/api/packages/source_span.
  [   +1 ms] IO  : HTTP GET https://pub.dartlang.org/api/packages/source_span
  [   +1 ms]     | Accept: application/vnd.pub.v2+json
  [        ]     | X-Pub-OS: linux
  [        ]     | X-Pub-Command: get
  [        ]     | X-Pub-Session-ID: E0E7DEC7-525C-44A8-91DC-5A6CDBA160F6
  [        ]     | X-Pub-Environment: flutter_cli:create
  [        ]     | user-agent: Dart pub 2.9.0-21.0.dev.flutter-20bf2fcf56
  [ +418 ms] IO  : HTTP response 200 OK for GET https://pub.dartlang.org/api/packages/source_span
  [        ]     | took 0:00:00.374598
  [        ]     | transfer-encoding: chunked
  [        ]     | date: Tue, 21 Jul 2020 11:57:38 GMT
  [        ]     | content-encoding: gzip
  [        ]     | vary: Accept-Encoding
  [        ]     | strict-transport-security: max-age=31536000; preload
  [        ]     | via: 1.1 google
  [        ]     | content-type: application/json; charset="utf-8"
  [        ]     | x-frame-options: SAMEORIGIN
  [        ]     | x-xss-protection: 1; mode=block
  [        ]     | x-content-type-options: nosniff
  [        ]     | server: dart:io with Shelf
  [        ] IO  : Get versions from https://pub.dartlang.org/api/packages/stack_trace.
  [        ] IO  : HTTP GET https://pub.dartlang.org/api/packages/stack_trace
  [        ]     | Accept: application/vnd.pub.v2+json
  [        ]     | X-Pub-OS: linux
  [        ]     | X-Pub-Command: get
  [        ]     | X-Pub-Session-ID: E0E7DEC7-525C-44A8-91DC-5A6CDBA160F6
  [        ]     | X-Pub-Environment: flutter_cli:create
  [        ]     | user-agent: Dart pub 2.9.0-21.0.dev.flutter-20bf2fcf56
  [ +367 ms] IO  : HTTP response 200 OK for GET https://pub.dartlang.org/api/packages/stack_trace
  [        ]     | took 0:00:00.402386
  [        ]     | transfer-encoding: chunked
  [        ]     | date: Tue, 21 Jul 2020 11:57:38 GMT
  [        ]     | content-encoding: gzip
  [        ]     | vary: Accept-Encoding
  [        ]     | strict-transport-security: max-age=31536000; preload
  [        ]     | via: 1.1 google
  [        ]     | content-type: application/json; charset="utf-8"
  [        ]     | x-frame-options: SAMEORIGIN
  [        ]     | x-xss-protection: 1; mode=block
  [        ]     | x-content-type-options: nosniff
  [        ]     | server: dart:io with Shelf
  [  +31 ms] IO  : Get versions from https://pub.dartlang.org/api/packages/stream_channel.
  [   +1 ms] IO  : HTTP GET https://pub.dartlang.org/api/packages/stream_channel
  [        ]     | Accept: application/vnd.pub.v2+json
  [        ]     | X-Pub-OS: linux
  [        ]     | X-Pub-Command: get
  [        ]     | X-Pub-Session-ID: E0E7DEC7-525C-44A8-91DC-5A6CDBA160F6
  [        ]     | X-Pub-Environment: flutter_cli:create
  [        ]     | user-agent: Dart pub 2.9.0-21.0.dev.flutter-20bf2fcf56
  [ +390 ms] IO  : HTTP response 200 OK for GET https://pub.dartlang.org/api/packages/stream_channel
  [        ]     | took 0:00:00.392512
  [        ]     | transfer-encoding: chunked
  [   +1 ms]     | date: Tue, 21 Jul 2020 11:57:39 GMT
  [        ]     | content-encoding: gzip
  [        ]     | vary: Accept-Encoding
  [        ]     | strict-transport-security: max-age=31536000; preload
  [        ]     | via: 1.1 google
  [        ]     | content-type: application/json; charset="utf-8"
  [        ]     | x-frame-options: SAMEORIGIN
  [        ]     | x-xss-protection: 1; mode=block
  [        ]     | x-content-type-options: nosniff
  [        ]     | server: dart:io with Shelf
  [   +2 ms] IO  : Get versions from https://pub.dartlang.org/api/packages/string_scanner.
  [   +1 ms] IO  : HTTP GET https://pub.dartlang.org/api/packages/string_scanner
  [        ]     | Accept: application/vnd.pub.v2+json
  [        ]     | X-Pub-OS: linux
  [        ]     | X-Pub-Command: get
  [        ]     | X-Pub-Session-ID: E0E7DEC7-525C-44A8-91DC-5A6CDBA160F6
  [        ]     | X-Pub-Environment: flutter_cli:create
  [        ]     | user-agent: Dart pub 2.9.0-21.0.dev.flutter-20bf2fcf56
  [ +386 ms] IO  : HTTP response 200 OK for GET https://pub.dartlang.org/api/packages/string_scanner
  [        ]     | took 0:00:00.391765
  [        ]     | transfer-encoding: chunked
  [        ]     | date: Tue, 21 Jul 2020 11:57:39 GMT
  [        ]     | content-encoding: gzip
  [        ]     | vary: Accept-Encoding
  [        ]     | strict-transport-security: max-age=31536000; preload
  [        ]     | via: 1.1 google
  [        ]     | content-type: application/json; charset="utf-8"
  [        ]     | x-frame-options: SAMEORIGIN
  [        ]     | x-xss-protection: 1; mode=block
  [        ]     | x-content-type-options: nosniff
  [        ]     | server: dart:io with Shelf
  [   +2 ms] IO  : Get versions from https://pub.dartlang.org/api/packages/term_glyph.
  [   +1 ms] IO  : HTTP GET https://pub.dartlang.org/api/packages/term_glyph
  [        ]     | Accept: application/vnd.pub.v2+json
  [        ]     | X-Pub-OS: linux
  [        ]     | X-Pub-Command: get
  [        ]     | X-Pub-Session-ID: E0E7DEC7-525C-44A8-91DC-5A6CDBA160F6
  [        ]     | X-Pub-Environment: flutter_cli:create
  [        ]     | user-agent: Dart pub 2.9.0-21.0.dev.flutter-20bf2fcf56
  [ +406 ms] IO  : HTTP response 200 OK for GET https://pub.dartlang.org/api/packages/term_glyph
  [        ]     | took 0:00:00.409333
  [        ]     | transfer-encoding: chunked
  [        ]     | date: Tue, 21 Jul 2020 11:57:40 GMT
  [        ]     | content-encoding: gzip
  [        ]     | vary: Accept-Encoding
  [        ]     | strict-transport-security: max-age=31536000; preload
  [        ]     | via: 1.1 google
  [        ]     | content-type: application/json; charset="utf-8"
  [        ]     | x-frame-options: SAMEORIGIN
  [        ]     | x-xss-protection: 1; mode=block
  [        ]     | x-content-type-options: nosniff
  [        ]     | server: dart:io with Shelf
  [   +5 ms] IO  : Get versions from https://pub.dartlang.org/api/packages/test_api.
  [   +1 ms] IO  : HTTP GET https://pub.dartlang.org/api/packages/test_api
  [        ]     | Accept: application/vnd.pub.v2+json
  [        ]     | X-Pub-OS: linux
  [        ]     | X-Pub-Command: get
  [        ]     | X-Pub-Session-ID: E0E7DEC7-525C-44A8-91DC-5A6CDBA160F6
  [        ]     | X-Pub-Environment: flutter_cli:create
  [        ]     | user-agent: Dart pub 2.9.0-21.0.dev.flutter-20bf2fcf56
  [ +369 ms] IO  : HTTP response 200 OK for GET https://pub.dartlang.org/api/packages/test_api
  [        ]     | took 0:00:00.373047
  [        ]     | transfer-encoding: chunked
  [        ]     | date: Tue, 21 Jul 2020 11:57:40 GMT
  [        ]     | content-encoding: gzip
  [        ]     | vary: Accept-Encoding
  [        ]     | strict-transport-security: max-age=31536000; preload
  [        ]     | via: 1.1 google
  [        ]     | content-type: application/json; charset="utf-8"
  [        ]     | x-frame-options: SAMEORIGIN
  [        ]     | x-xss-protection: 1; mode=block
  [        ]     | x-content-type-options: nosniff
  [        ]     | server: dart:io with Shelf
  [  +14 ms] IO  : Get versions from https://pub.dartlang.org/api/packages/typed_data.
  [   +1 ms] IO  : HTTP GET https://pub.dartlang.org/api/packages/typed_data
  [        ]     | Accept: application/vnd.pub.v2+json
  [   +1 ms]     | X-Pub-OS: linux
  [        ]     | X-Pub-Command: get
  [        ]     | X-Pub-Session-ID: E0E7DEC7-525C-44A8-91DC-5A6CDBA160F6
  [        ]     | X-Pub-Environment: flutter_cli:create
  [        ]     | user-agent: Dart pub 2.9.0-21.0.dev.flutter-20bf2fcf56
  [ +360 ms] IO  : HTTP response 200 OK for GET https://pub.dartlang.org/api/packages/typed_data
  [        ]     | took 0:00:00.364430
  [        ]     | transfer-encoding: chunked
  [        ]     | date: Tue, 21 Jul 2020 11:57:40 GMT
  [        ]     | content-encoding: gzip
  [        ]     | vary: Accept-Encoding
  [        ]     | strict-transport-security: max-age=31536000; preload
  [        ]     | via: 1.1 google
  [        ]     | content-type: application/json; charset="utf-8"
  [        ]     | x-frame-options: SAMEORIGIN
  [        ]     | x-xss-protection: 1; mode=block
  [        ]     | x-content-type-options: nosniff
  [        ]     | server: dart:io with Shelf
  [  +10 ms] IO  : Get versions from https://pub.dartlang.org/api/packages/vector_math.
  [   +1 ms] IO  : HTTP GET https://pub.dartlang.org/api/packages/vector_math
  [   +1 ms]     | Accept: application/vnd.pub.v2+json
  [        ]     | X-Pub-OS: linux
  [        ]     | X-Pub-Command: get
  [        ]     | X-Pub-Session-ID: E0E7DEC7-525C-44A8-91DC-5A6CDBA160F6
  [   +1 ms]     | X-Pub-Environment: flutter_cli:create
  [        ]     | user-agent: Dart pub 2.9.0-21.0.dev.flutter-20bf2fcf56
  [ +192 ms] IO  : HTTP response 200 OK for GET https://pub.dartlang.org/api/packages/clock
  [        ]     | took 0:00:03.496772
  [        ]     | transfer-encoding: chunked
  [        ]     | date: Tue, 21 Jul 2020 11:57:41 GMT
  [        ]     | content-encoding: gzip
  [        ]     | vary: Accept-Encoding
  [        ]     | strict-transport-security: max-age=31536000; preload
  [        ]     | via: 1.1 google
  [        ]     | content-type: application/json; charset="utf-8"
  [        ]     | x-frame-options: SAMEORIGIN
  [        ]     | x-xss-protection: 1; mode=block
  [        ]     | x-content-type-options: nosniff
  [        ]     | server: dart:io with Shelf
  [   +8 ms] IO  : HTTP response 200 OK for GET https://pub.dartlang.org/api/packages/boolean_selector
  [   +1 ms]     | took 0:00:03.516425
  [        ]     | transfer-encoding: chunked
  [        ]     | date: Tue, 21 Jul 2020 11:57:41 GMT
  [        ]     | content-encoding: gzip
  [        ]     | vary: Accept-Encoding
  [        ]     | strict-transport-security: max-age=31536000; preload
  [        ]     | via: 1.1 google
  [        ]     | content-type: application/json; charset="utf-8"
  [        ]     | x-frame-options: SAMEORIGIN
  [        ]     | x-xss-protection: 1; mode=block
  [        ]     | x-content-type-options: nosniff
  [        ]     | server: dart:io with Shelf
  [  +17 ms] IO  : HTTP response 200 OK for GET https://pub.dartlang.org/api/packages/path
  [        ]     | took 0:00:03.529415
  [        ]     | transfer-encoding: chunked
  [        ]     | date: Tue, 21 Jul 2020 11:57:41 GMT
  [        ]     | content-encoding: gzip
  [   +1 ms]     | vary: Accept-Encoding
  [        ]     | strict-transport-security: max-age=31536000; preload
  [        ]     | via: 1.1 google
  [        ]     | content-type: application/json; charset="utf-8"
  [        ]     | x-frame-options: SAMEORIGIN
  [        ]     | x-xss-protection: 1; mode=block
  [        ]     | x-content-type-options: nosniff
  [        ]     | server: dart:io with Shelf
  [   +1 ms] IO  : HTTP response 200 OK for GET https://pub.dartlang.org/api/packages/charcode
  [        ]     | took 0:00:03.547784
  [        ]     | transfer-encoding: chunked
  [        ]     | date: Tue, 21 Jul 2020 11:57:41 GMT
  [        ]     | content-encoding: gzip
  [        ]     | vary: Accept-Encoding
  [        ]     | strict-transport-security: max-age=31536000; preload
  [        ]     | via: 1.1 google
  [        ]     | content-type: application/json; charset="utf-8"
  [        ]     | x-frame-options: SAMEORIGIN
  [        ]     | x-xss-protection: 1; mode=block
  [        ]     | x-content-type-options: nosniff
  [        ]     | server: dart:io with Shelf
  [   +1 ms] IO  : HTTP response 200 OK for GET https://pub.dartlang.org/api/packages/characters
  [        ]     | took 0:00:03.555278
  [        ]     | transfer-encoding: chunked
  [        ]     | date: Tue, 21 Jul 2020 11:57:41 GMT
  [        ]     | content-encoding: gzip
  [        ]     | vary: Accept-Encoding
  [        ]     | strict-transport-security: max-age=31536000; preload
  [        ]     | via: 1.1 google
  [        ]     | content-type: application/json; charset="utf-8"
  [        ]     | x-frame-options: SAMEORIGIN
  [        ]     | x-xss-protection: 1; mode=block
  [        ]     | x-content-type-options: nosniff
  [        ]     | server: dart:io with Shelf
  [        ] IO  : HTTP response 200 OK for GET https://pub.dartlang.org/api/packages/meta
  [        ]     | took 0:00:03.552552
  [        ]     | transfer-encoding: chunked
  [        ]     | date: Tue, 21 Jul 2020 11:57:41 GMT
  [        ]     | content-encoding: gzip
  [        ]     | vary: Accept-Encoding
  [        ]     | strict-transport-security: max-age=31536000; preload
  [        ]     | via: 1.1 google
  [        ]     | content-type: application/json; charset="utf-8"
  [        ]     | x-frame-options: SAMEORIGIN
  [        ]     | x-xss-protection: 1; mode=block
  [        ]     | x-content-type-options: nosniff
  [        ]     | server: dart:io with Shelf
  [   +1 ms] IO  : HTTP response 200 OK for GET https://pub.dartlang.org/api/packages/collection
  [   +1 ms]     | took 0:00:03.565005
  [   +1 ms]     | transfer-encoding: chunked
  [        ]     | date: Tue, 21 Jul 2020 11:57:41 GMT
  [        ]     | content-encoding: gzip
  [        ]     | vary: Accept-Encoding
  [        ]     | strict-transport-security: max-age=31536000; preload
  [        ]     | via: 1.1 google
  [        ]     | content-type: application/json; charset="utf-8"
  [        ]     | x-frame-options: SAMEORIGIN
  [        ]     | x-xss-protection: 1; mode=block
  [        ]     | x-content-type-options: nosniff
  [        ]     | server: dart:io with Shelf
  [  +33 ms] IO  : HTTP response 200 OK for GET https://pub.dartlang.org/api/packages/fake_async
  [        ]     | took 0:00:03.615663
  [        ]     | transfer-encoding: chunked
  [        ]     | date: Tue, 21 Jul 2020 11:57:41 GMT
  [        ]     | content-encoding: gzip
  [        ]     | vary: Accept-Encoding
  [        ]     | strict-transport-security: max-age=31536000; preload
  [        ]     | via: 1.1 google
  [        ]     | content-type: application/json; charset="utf-8"
  [        ]     | x-frame-options: SAMEORIGIN
  [        ]     | x-xss-protection: 1; mode=block
  [        ]     | x-content-type-options: nosniff
  [        ]     | server: dart:io with Shelf
  [   +1 ms] IO  : HTTP response 200 OK for GET https://pub.dartlang.org/api/packages/matcher
  [   +1 ms]     | took 0:00:03.624263
  [        ]     | transfer-encoding: chunked
  [        ]     | date: Tue, 21 Jul 2020 11:57:41 GMT
  [        ]     | content-encoding: gzip
  [        ]     | vary: Accept-Encoding
  [        ]     | strict-transport-security: max-age=31536000; preload
  [   +1 ms]     | via: 1.1 google
  [        ]     | content-type: application/json; charset="utf-8"
  [        ]     | x-frame-options: SAMEORIGIN
  [        ]     | x-xss-protection: 1; mode=block
  [        ]     | x-content-type-options: nosniff
  [        ]     | server: dart:io with Shelf
  [  +64 ms] IO  : HTTP response 200 OK for GET https://pub.dartlang.org/api/packages/vector_math
  [        ]     | took 0:00:00.404185
  [        ]     | transfer-encoding: chunked
  [        ]     | date: Tue, 21 Jul 2020 11:57:41 GMT
  [        ]     | content-encoding: gzip
  [        ]     | vary: Accept-Encoding
  [        ]     | strict-transport-security: max-age=31536000; preload
  [        ]     | via: 1.1 google
  [        ]     | content-type: application/json; charset="utf-8"
  [        ]     | x-frame-options: SAMEORIGIN
  [        ]     | x-xss-protection: 1; mode=block
  [        ]     | x-content-type-options: nosniff
  [        ]     | server: dart:io with Shelf
  [  +44 ms] SLVR:       selecting cupertino_icons 0.1.3
  [  +14 ms] SLVR:       fact: every version of flutter from sdk depends on characters 1.1.0-nullsafety
  [   +1 ms] SLVR:       fact: every version of flutter from sdk depends on collection 1.15.0-nullsafety
  [        ] SLVR:       fact: every version of flutter from sdk depends on meta 1.3.0-nullsafety
  [        ] SLVR:       fact: every version of flutter from sdk depends on sky_engine any from sdk
  [        ] SLVR:       fact: every version of flutter from sdk depends on typed_data 1.3.0-nullsafety
  [        ] SLVR:       fact: every version of flutter from sdk depends on vector_math 2.1.0-nullsafety
  [        ] SLVR:         selecting flutter 0.0.0 from sdk
  [        ] SLVR:         derived: sky_engine any from sdk
  [  +28 ms] SLVR:           selecting vector_math 2.1.0-nullsafety
  [  +30 ms] SLVR:           fact: typed_data >=1.3.0-nnbd <1.3.0-nullsafety.1 depends on collection >=1.15.0-nnbd <1.15.0
  [   +1 ms] SLVR:             selecting typed_data 1.3.0-nullsafety
  [  +80 ms] SLVR:             fact: test_api >=0.2.5 depends on async ^2.0.0
  [   +1 ms] SLVR:             fact: test_api >=0.2.14 depends on boolean_selector >=1.0.0 <3.0.0
  [        ] SLVR:             fact: every version of test_api depends on collection ^1.8.0
  [  +14 ms] SLVR:             fact: test_api >=0.2.17 <0.2.18-∞ depends on matcher >=0.12.6 <0.12.9
  [   +4 ms] SLVR:             fact: every version of test_api depends on meta ^1.1.5
  [        ] SLVR:             fact: every version of test_api depends on path ^1.2.0
  [        ] SLVR:             fact: every version of test_api depends on source_span ^1.4.0
  [        ] SLVR:             fact: every version of test_api depends on stack_trace ^1.9.0
  [        ] SLVR:             fact: test_api >=0.2.4 depends on stream_channel >=1.7.0 <3.0.0
  [        ] SLVR:             fact: test_api >=0.2.5 depends on string_scanner ^1.0.0
  [   +1 ms] SLVR:             fact: every version of test_api depends on term_glyph ^1.0.0
  [   +1 ms] SLVR:               selecting test_api 0.2.17
  [   +6 ms] SLVR:                 selecting term_glyph 1.1.0
  [  +18 ms] SLVR:                 fact: string_scanner >=1.0.3 depends on charcode ^1.1.0
  [   +1 ms] SLVR:                 fact: string_scanner >=1.0.4 depends on meta ^1.1.0
  [        ] SLVR:                 fact: string_scanner >=1.0.3 depends on source_span ^1.4.0
  [        ] SLVR:                   selecting string_scanner 1.0.5
  [  +24 ms] SLVR:                   fact: stream_channel >=1.6.8 depends on async >=1.11.0 <3.0.0
  [   +1 ms] SLVR:                     selecting stream_channel 2.0.0
  [  +27 ms] SLVR:                     fact: stack_trace >=1.9.3 depends on path ^1.2.0
  [   +1 ms] SLVR:                       selecting stack_trace 1.9.5
  [  +37 ms] SLVR:                       fact: source_span >=1.4.1 depends on charcode ^1.0.0
  [   +1 ms] SLVR:                       fact: source_span >=1.6.0 depends on collection ^1.8.0
  [        ] SLVR:                       fact: source_span >=1.6.0 depends on meta >=0.9.0 <2.0.0
  [        ] SLVR:                       fact: source_span >=1.4.1 depends on path ^1.2.0
  [        ] SLVR:                       fact: source_span >=1.5.0 depends on term_glyph ^1.0.0
  [        ] SLVR:                         selecting source_span 1.7.0
  [  +20 ms] SLVR:                           selecting path 1.7.0
  [  +16 ms] SLVR:                             selecting meta 1.3.0-nullsafety
  [  +31 ms] SLVR:                             fact: matcher >=0.12.3+1 depends on stack_trace ^1.2.0
  [   +1 ms] SLVR:                               selecting matcher 0.12.8
  [  +17 ms] SLVR:                               fact: fake_async >=1.0.1 depends on clock ^1.0.0
  [   +1 ms] SLVR:                               fact: fake_async >=1.0.1 depends on collection ^1.8.0
  [   +1 ms] SLVR:                                 selecting fake_async 1.1.0
  [   +6 ms] SLVR:                                   selecting collection 1.15.0-nullsafety
  [   +5 ms] SLVR:                                   fact: clock >=1.0.1 depends on meta >=0.9.0 <2.0.0
  [        ] SLVR:                                     selecting clock 1.0.1
  [   +3 ms] SLVR:                                       selecting charcode 1.1.3
  [   +4 ms] SLVR:                                         selecting characters 1.1.0-nullsafety
  [   +5 ms] SLVR:                                         fact: boolean_selector >=1.0.4 depends on source_span ^1.0.0
  [        ] SLVR:                                         fact: boolean_selector >=2.0.0 depends on string_scanner ^1.0.0
  [        ] SLVR:                                           selecting boolean_selector 2.0.0
  [   +9 ms] SLVR:                                           fact: async >=2.0.8 depends on collection ^1.5.0
  [        ] SLVR:                                             selecting async 2.4.2
  [   +1 ms] SLVR:                                               selecting sky_engine 0.0.99 from sdk
  [   +4 ms] SLVR: Version solving took 0:00:05.892360 seconds.
  [        ]     | Tried 1 solutions.
  [        ] FINE: Resolving dependencies finished (5.906s).
  [   +8 ms] MSG : + async 2.4.2
  [        ]     | + boolean_selector 2.0.0
  [        ]     | + characters 1.1.0-nullsafety (1.1.0-nullsafety.1 available)
  [        ]     | + charcode 1.1.3
  [        ]     | + clock 1.0.1
  [        ]     | + collection 1.15.0-nullsafety (1.15.0-nullsafety.1 available)
  [        ]     | + cupertino_icons 0.1.3
  [        ]     | + fake_async 1.1.0
  [        ]     | + flutter 0.0.0 from sdk flutter
  [        ]     | + flutter_test 0.0.0 from sdk flutter
  [        ]     | + matcher 0.12.8 (0.12.9 available)
  [        ]     | + meta 1.3.0-nullsafety (1.3.0-nullsafety.1 available)
  [        ]     | + path 1.7.0
  [        ]     | + sky_engine 0.0.99 from sdk flutter
  [        ]     | + source_span 1.7.0
  [        ]     | + stack_trace 1.9.5
  [        ]     | + stream_channel 2.0.0
  [        ]     | + string_scanner 1.0.5
  [        ]     | + term_glyph 1.1.0
  [        ]     | + test_api 0.2.17 (0.2.18 available)
  [        ]     | + typed_data 1.3.0-nullsafety (1.3.0-nullsafety.1 available)
  [        ]     | + vector_math 2.1.0-nullsafety (2.1.0-nullsafety.1 available)
  [  +53 ms] IO  : Writing 3498 characters to text file ./pubspec.lock.
  [        ] FINE: Contents:
  [        ]     | # Generated by pub
  [        ]     | # See https://dart.dev/tools/pub/glossary#lockfile
  [        ]     | packages:
  [        ]     |   async:
  [        ]     |     dependency: transitive
  [        ]     |     description:
  [        ]     |       name: async
  [        ]     |       url: "https://pub.dartlang.org"
  [        ]     |     source: hosted
  [        ]     |     version: "2.4.2"
  [        ]     |   boolean_selector:
  [        ]     |     dependency: transitive
  [        ]     |     description:
  [        ]     |       name: boolean_selector
  [        ]     |       url: "https://pub.dartlang.org"
  [        ]     |     source: hosted
  [        ]     |     version: "2.0.0"
  [        ]     |   characters:
  [        ]     |     dependency: transitive
  [        ]     |     description:
  [        ]     |       name: characters
  [        ]     |       url: "https://pub.dartlang.org"
  [        ]     |     source: hosted
  [        ]     |     version: "1.1.0-nullsafety"
  [        ]     |   charcode:
  [        ]     |     dependency: transitive
  [        ]     |     description:
  [        ]     |       name: charcode
  [        ]     |       url: "https://pub.dartlang.org"
  [        ]     |     source: hosted
  [        ]     |     version: "1.1.3"
  [        ]     |   clock:
  [        ]     |     dependency: transitive
  [        ]     |     description:
  [        ]     |       name: clock
  [        ]     |       url: "https://pub.dartlang.org"
  [        ]     |     source: hosted
  [        ]     |     version: "1.0.1"
  [        ]     |   collection:
  [        ]     |     dependency: transitive
  [        ]     |     description:
  [        ]     |       name: collection
  [        ]     |       url: "https://pub.dartlang.org"
  [        ]     |     source: hosted
  [        ]     |     version: "1.15.0-nullsafety"
  [        ]     |   cupertino_icons:
  [        ]     |     dependency: "direct main"
  [        ]     |     description:
  [        ]     |       name: cupertino_icons
  [        ]     |       url: "https://pub.dartlang.org"
  [        ]     |     source: hosted
  [        ]     |     version: "0.1.3"
  [        ]     |   fake_async:
  [        ]     |     dependency: transitive
  [        ]     |     description:
  [        ]     |       name: fake_async
  [        ]     |       url: "https://pub.dartlang.org"
  [        ]     |     source: hosted
  [        ]     |     version: "1.1.0"
  [        ]     |   flutter:
  [        ]     |     dependency: "direct main"
  [        ]     |     description: flutter
  [        ]     |     source: sdk
  [        ]     |     version: "0.0.0"
  [        ]     |   flutter_test:
  [        ]     |     dependency: "direct dev"
  [        ]     |     description: flutter
  [        ]     |     source: sdk
  [        ]     |     version: "0.0.0"
  [        ]     |   matcher:
  [        ]     |     dependency: transitive
  [        ]     |     description:
  [        ]     |       name: matcher
  [        ]     |       url: "https://pub.dartlang.org"
  [        ]     |     source: hosted
  [        ]     |     version: "0.12.8"
  [        ]     |   meta:
  [        ]     |     dependency: transitive
  [        ]     |     description:
  [        ]     |       name: meta
  [        ]     |       url: "https://pub.dartlang.org"
  [        ]     |     source: hosted
  [        ]     |     version: "1.3.0-nullsafety"
  [        ]     |   path:
  [        ]     |     dependency: transitive
  [        ]     |     description:
  [        ]     |       name: path
  [        ]     |       url: "https://pub.dartlang.org"
  [        ]     |     source: hosted
  [        ]     |     version: "1.7.0"
  [        ]     |   sky_engine:
  [        ]     |     dependency: transitive
  [        ]     |     description: flutter
  [        ]     |     source: sdk
  [        ]     |     version: "0.0.99"
  [        ]     |   source_span:
  [        ]     |     dependency: transitive
  [        ]     |     description:
  [        ]     |       name: source_span
  [        ]     |       url: "https://pub.dartlang.org"
  [        ]     |     source: hosted
  [        ]     |     version: "1.7.0"
  [        ]     |   stack_trace:
  [        ]     |     dependency: transitive
  [        ]     |     description:
  [        ]     |       name: stack_trace
  [        ]     |       url: "https://pub.dartlang.org"
  [        ]     |     source: hosted
  [        ]     |     version: "1.9.5"
  [        ]     |   stream_channel:
  [        ]     |     dependency: transitive
  [        ]     |     description:
  [        ]     |       name: stream_channel
  [        ]     |       url: "https://pub.dartlang.org"
  [        ]     |     source: hosted
  [        ]     |     version: "2.0.0"
  [        ]     |   string_scanner:
  [        ]     |     dependency: transitive
  [        ]     |     description:
  [        ]     |       name: string_scanner
  [        ]     |       url: "https://pub.dartlang.org"
  [        ]     |     source: hosted
  [        ]     |     version: "1.0.5"
  [        ]     |   term_glyph:
  [        ]     |     dependency: transitive
  [        ]     |     description:
  [        ]     |       name: term_glyph
  [        ]     |       url: "https://pub.dartlang.org"
  [        ]     |     source: hosted
  [        ]     |     version: "1.1.0"
  [        ]     |   test_api:
  [        ]     |     dependency: transitive
  [        ]     |     description:
  [        ]     |       name: test_api
  [        ]     |       url: "https://pub.dartlang.org"
  [        ]     |     source: hosted
  [        ]     |     version: "0.2.17"
  [        ]     |   typed_data:
  [        ]     |     dependency: transitive
  [        ]     |     description:
  [        ]     |       name: typed_data
  [        ]     |       url: "https://pub.dartlang.org"
  [        ]     |     source: hosted
  [        ]     |     version: "1.3.0-nullsafety"
  [        ]     |   vector_math:
  [        ]     |     dependency: transitive
  [        ]     |     description:
  [        ]     |       name: vector_math
  [        ]     |       url: "https://pub.dartlang.org"
  [        ]     |     source: hosted
  [        ]     |     version: "2.1.0-nullsafety"
  [        ]     | sdks:
  [        ]     |   dart: ">=2.9.0-18.0 <2.9.0"
  [   +2 ms] IO  : Writing 2577 characters to text file ./.packages.
  [        ] FINE: Contents:
  [        ]     | # Generated by pub on 2020-07-21 17:27:41.922353.
  [        ]     | async:file:///home/user/snap/flutter/common/flutter/.pub-cache/hosted/pub.dartlang.org/async-2.4.2/lib/
  [        ]     | boolean_selector:file:///home/user/snap/flutter/common/flutter/.pub-cache/hosted/pub.dartlang.org/boolean_selector-2.0.0/lib/
  [   +1 ms]     | characters:file:///home/user/snap/flutter/common/flutter/.pub-cache/hosted/pub.dartlang.org/characters-1.1.0-nullsafety/lib/
  [        ]     | charcode:file:///home/user/snap/flutter/common/flutter/.pub-cache/hosted/pub.dartlang.org/charcode-1.1.3/lib/
  [        ]     | clock:file:///home/user/snap/flutter/common/flutter/.pub-cache/hosted/pub.dartlang.org/clock-1.0.1/lib/
  [        ]     | collection:file:///home/user/snap/flutter/common/flutter/.pub-cache/hosted/pub.dartlang.org/collection-1.15.0-nullsafety/lib/
  [        ]     | cupertino_icons:file:///home/user/snap/flutter/common/flutter/.pub-cache/hosted/pub.dartlang.org/cupertino_icons-0.1.3/lib/
  [        ]     | fake_async:file:///home/user/snap/flutter/common/flutter/.pub-cache/hosted/pub.dartlang.org/fake_async-1.1.0/lib/
  [        ]     | flutter:file:///home/user/snap/flutter/common/flutter/packages/flutter/lib/
  [        ]     | flutter_test:file:///home/user/snap/flutter/common/flutter/packages/flutter_test/lib/
  [        ]     | matcher:file:///home/user/snap/flutter/common/flutter/.pub-cache/hosted/pub.dartlang.org/matcher-0.12.8/lib/
  [        ]     | meta:file:///home/user/snap/flutter/common/flutter/.pub-cache/hosted/pub.dartlang.org/meta-1.3.0-nullsafety/lib/
  [        ]     | path:file:///home/user/snap/flutter/common/flutter/.pub-cache/hosted/pub.dartlang.org/path-1.7.0/lib/
  [        ]     | sky_engine:file:///home/user/snap/flutter/common/flutter/bin/cache/pkg/sky_engine/lib/
  [        ]     | source_span:file:///home/user/snap/flutter/common/flutter/.pub-cache/hosted/pub.dartlang.org/source_span-1.7.0/lib/
  [        ]     | stack_trace:file:///home/user/snap/flutter/common/flutter/.pub-cache/hosted/pub.dartlang.org/stack_trace-1.9.5/lib/
  [        ]     | stream_channel:file:///home/user/snap/flutter/common/flutter/.pub-cache/hosted/pub.dartlang.org/stream_channel-2.0.0/lib/
  [        ]     | string_scanner:file:///home/user/snap/flutter/common/flutter/.pub-cache/hosted/pub.dartlang.org/string_scanner-1.0.5/lib/
  [        ]     | term_glyph:file:///home/user/snap/flutter/common/flutter/.pub-cache/hosted/pub.dartlang.org/term_glyph-1.1.0/lib/
  [        ]     | test_api:file:///home/user/snap/flutter/common/flutter/.pub-cache/hosted/pub.dartlang.org/test_api-0.2.17/lib/
  [        ]     | typed_data:file:///home/user/snap/flutter/common/flutter/.pub-cache/hosted/pub.dartlang.org/typed_data-1.3.0-nullsafety/lib/
  [   +1 ms]     | vector_math:file:///home/user/snap/flutter/common/flutter/.pub-cache/hosted/pub.dartlang.org/vector_math-2.1.0-nullsafety/lib/
  [        ]     | testapp_dev_boot_1:lib/
  [        ] IO  : Writing 5096 characters to text file ./.dart_tool/package_config.json.
  [        ] FINE: Contents:
  [        ]     | {
  [        ]     |   "configVersion": 2,
  [        ]     |   "packages": [
  [        ]     |     {
  [        ]     |       "name": "async",
  [        ]     |       "rootUri": "file:///home/user/snap/flutter/common/flutter/.pub-cache/hosted/pub.dartlang.org/async-2.4.2",
  [        ]     |       "packageUri": "lib/",
  [        ]     |       "languageVersion": "2.2"
  [        ]     |     },
  [        ]     |     {
  [        ]     |       "name": "boolean_selector",
  [        ]     |       "rootUri": "file:///home/user/snap/flutter/common/flutter/.pub-cache/hosted/pub.dartlang.org/boolean_selector-2.0.0",
  [        ]     |       "packageUri": "lib/",
  [        ]     |       "languageVersion": "2.4"
  [   +1 ms]     |     },
  [        ]     |     {
  [        ]     |       "name": "characters",
  [        ]     |       "rootUri": "file:///home/user/snap/flutter/common/flutter/.pub-cache/hosted/pub.dartlang.org/characters-1.1.0-nullsafety",
  [        ]     |       "packageUri": "lib/",
  [        ]     |       "languageVersion": "2.9"
  [        ]     |     },
  [        ]     |     {
  [        ]     |       "name": "charcode",
  [        ]     |       "rootUri": "file:///home/user/snap/flutter/common/flutter/.pub-cache/hosted/pub.dartlang.org/charcode-1.1.3",
  [        ]     |       "packageUri": "lib/",
  [        ]     |       "languageVersion": "2.0"
  [        ]     |     },
  [        ]     |     {
  [        ]     |       "name": "clock",
  [        ]     |       "rootUri": "file:///home/user/snap/flutter/common/flutter/.pub-cache/hosted/pub.dartlang.org/clock-1.0.1",
  [        ]     |       "packageUri": "lib/",
  [        ]     |       "languageVersion": "2.0"
  [        ]     |     },
  [        ]     |     {
  [        ]     |       "name": "collection",
  [        ]     |       "rootUri": "file:///home/user/snap/flutter/common/flutter/.pub-cache/hosted/pub.dartlang.org/collection-1.15.0-nullsafety",
  [        ]     |       "packageUri": "lib/",
  [        ]     |       "languageVersion": "2.9"
  [        ]     |     },
  [        ]     |     {
  [        ]     |       "name": "cupertino_icons",
  [        ]     |       "rootUri": "file:///home/user/snap/flutter/common/flutter/.pub-cache/hosted/pub.dartlang.org/cupertino_icons-0.1.3",
  [        ]     |       "packageUri": "lib/",
  [        ]     |       "languageVersion": "2.0"
  [        ]     |     },
  [        ]     |     {
  [        ]     |       "name": "fake_async",
  [        ]     |       "rootUri": "file:///home/user/snap/flutter/common/flutter/.pub-cache/hosted/pub.dartlang.org/fake_async-1.1.0",
  [        ]     |       "packageUri": "lib/",
  [        ]     |       "languageVersion": "2.2"
  [        ]     |     },
  [        ]     |     {
  [        ]     |       "name": "flutter",
  [        ]     |       "rootUri": "file:///home/user/snap/flutter/common/flutter/packages/flutter",
  [        ]     |       "packageUri": "lib/",
  [        ]     |       "languageVersion": "2.9"
  [        ]     |     },
  [        ]     |     {
  [        ]     |       "name": "flutter_test",
  [        ]     |       "rootUri": "file:///home/user/snap/flutter/common/flutter/packages/flutter_test",
  [        ]     |       "packageUri": "lib/",
  [        ]     |       "languageVersion": "2.2"
  [        ]     |     },
  [        ]     |     {
  [        ]     |       "name": "matcher",
  [        ]     |       "rootUri": "file:///home/user/snap/flutter/common/flutter/.pub-cache/hosted/pub.dartlang.org/matcher-0.12.8",
  [        ]     |       "packageUri": "lib/",
  [        ]     |       "languageVersion": "2.4"
  [        ]     |     },
  [        ]     |     {
  [        ]     |       "name": "meta",
  [        ]     |       "rootUri": "file:///home/user/snap/flutter/common/flutter/.pub-cache/hosted/pub.dartlang.org/meta-1.3.0-nullsafety",
  [        ]     |       "packageUri": "lib/",
  [        ]     |       "languageVersion": "2.9"
  [        ]     |     },
  [        ]     |     {
  [        ]     |       "name": "path",
  [        ]     |       "rootUri": "file:///home/user/snap/flutter/common/flutter/.pub-cache/hosted/pub.dartlang.org/path-1.7.0",
  [        ]     |       "packageUri": "lib/",
  [        ]     |       "languageVersion": "2.0"
  [        ]     |     },
  [        ]     |     {
  [        ]     |       "name": "sky_engine",
  [        ]     |       "rootUri": "file:///home/user/snap/flutter/common/flutter/bin/cache/pkg/sky_engine",
  [        ]     |       "packageUri": "lib/",
  [        ]     |       "languageVersion": "1.11"
  [        ]     |     },
  [        ]     |     {
  [        ]     |       "name": "source_span",
  [        ]     |       "rootUri": "file:///home/user/snap/flutter/common/flutter/.pub-cache/hosted/pub.dartlang.org/source_span-1.7.0",
  [        ]     |       "packageUri": "lib/",
  [        ]     |       "languageVersion": "2.6"
  [        ]     |     },
  [        ]     |     {
  [        ]     |       "name": "stack_trace",
  [        ]     |       "rootUri": "file:///home/user/snap/flutter/common/flutter/.pub-cache/hosted/pub.dartlang.org/stack_trace-1.9.5",
  [        ]     |       "packageUri": "lib/",
  [        ]     |       "languageVersion": "2.0"
  [        ]     |     },
  [        ]     |     {
  [        ]     |       "name": "stream_channel",
  [        ]     |       "rootUri": "file:///home/user/snap/flutter/common/flutter/.pub-cache/hosted/pub.dartlang.org/stream_channel-2.0.0",
  [        ]     |       "packageUri": "lib/",
  [        ]     |       "languageVersion": "2.0"
  [        ]     |     },
  [        ]     |     {
  [        ]     |       "name": "string_scanner",
  [        ]     |       "rootUri": "file:///home/user/snap/flutter/common/flutter/.pub-cache/hosted/pub.dartlang.org/string_scanner-1.0.5",
  [        ]     |       "packageUri": "lib/",
  [        ]     |       "languageVersion": "2.0"
  [        ]     |     },
  [        ]     |     {
  [        ]     |       "name": "term_glyph",
  [        ]     |       "rootUri": "file:///home/user/snap/flutter/common/flutter/.pub-cache/hosted/pub.dartlang.org/term_glyph-1.1.0",
  [        ]     |       "packageUri": "lib/",
  [        ]     |       "languageVersion": "1.8"
  [        ]     |     },
  [        ]     |     {
  [        ]     |       "name": "test_api",
  [        ]     |       "rootUri": "file:///home/user/snap/flutter/common/flutter/.pub-cache/hosted/pub.dartlang.org/test_api-0.2.17",
  [        ]     |       "packageUri": "lib/",
  [        ]     |       "languageVersion": "2.7"
  [        ]     |     },
  [        ]     |     {
  [        ]     |       "name": "typed_data",
  [        ]     |       "rootUri": "file:///home/user/snap/flutter/common/flutter/.pub-cache/hosted/pub.dartlang.org/typed_data-1.3.0-nullsafety",
  [        ]     |       "packageUri": "lib/",
  [        ]     |       "languageVersion": "2.9"
  [        ]     |     },
  [        ]     |     {
  [        ]     |       "name": "vector_math",
  [        ]     |       "rootUri": "file:///home/user/snap/flutter/common/flutter/.pub-cache/hosted/pub.dartlang.org/vector_math-2.1.0-nullsafety",
  [        ]     |       "packageUri": "lib/",
  [        ]     |       "languageVersion": "2.9"
  [        ]     |     },
  [        ]     |     {
  [        ]     |       "name": "testapp_dev_boot_1",
  [        ]     |       "rootUri": "../",
  [        ]     |       "packageUri": "lib/",
  [        ]     |       "languageVersion": "2.7"
  [        ]     |     }
  [        ]     |   ],
  [        ]     |   "generated": "2020-07-21T11:57:41.944180Z",
  [        ]     |   "generator": "pub",
  [        ]     |   "generatorVersion": "2.9.0-21.0.dev.flutter-20bf2fcf56"
  [        ]     | }
  [   +3 ms] MSG : Changed 22 dependencies!
  [  +27 ms] Running "flutter pub get" in testapp_dev_boot_1... (completed in 6.2s)
  [ +201 ms] Generating /home/user/flutter_projects/testapp_dev_boot_1/android/app/src/main/java/io/flutter/plugins/GeneratedPluginRegistrant.java
  [   +6 ms] Wrote 71 files.
  [        ]
             All done!
  [  +18 ms] executing: /home/user/android-studio/jre/bin/java -version
  [ +263 ms] Exit code 0 from: /home/user/android-studio/jre/bin/java -version
  [        ] openjdk version "1.8.0_242-release"
             OpenJDK Runtime Environment (build 1.8.0_242-release-1644-b3-6222593)
             OpenJDK 64-Bit Server VM (build 25.242-b3-6222593, mixed mode)
  [  +35 ms] executing: /home/user/android-studio/jre/bin/java -version
  [  +73 ms] Exit code 0 from: /home/user/android-studio/jre/bin/java -version
  [        ] openjdk version "1.8.0_242-release"
             OpenJDK Runtime Environment (build 1.8.0_242-release-1644-b3-6222593)
             OpenJDK 64-Bit Server VM (build 25.242-b3-6222593, mixed mode)
  [   +6 ms] executing: [/home/user/snap/flutter/common/flutter/] git -c log.showSignature=false log -n 1 --pretty=format:%ar
  [   +6 ms] Exit code 0 from: git -c log.showSignature=false log -n 1 --pretty=format:%ar
  [        ] 7 days ago
  [  +14 ms] executing: /home/user/snap/flutter/common/flutter/bin/cache/artifacts/engine/android-arm-profile/linux-x64/gen_snapshot
  [  +17 ms] Exit code 255 from: /home/user/snap/flutter/common/flutter/bin/cache/artifacts/engine/android-arm-profile/linux-x64/gen_snapshot
  [        ] At least one input is required
             Usage: gen_snapshot [<vm-flags>] [<options>] <dart-kernel-file>

             Common options:
             --help
               Display this message (add --verbose for information about all VM options).
             --version
               Print the SDK version.

             To create a core snapshot:
             --snapshot_kind=core
             --vm_snapshot_data=<output-file>
             --isolate_snapshot_data=<output-file>
             <dart-kernel-file>

             To create an AOT application snapshot as assembly suitable for compilation
             as a static or dynamic library:
             --snapshot_kind=app-aot-assembly
             --assembly=<output-file>
             [--strip]
             [--obfuscate]
             [--save-debugging-info=<debug-filename>]
             [--save-obfuscation-map=<map-filename>]
             <dart-kernel-file>

             To create an AOT application snapshot as an ELF shared library:
             --snapshot_kind=app-aot-elf
             --elf=<output-file>
             [--strip]
             [--obfuscate]
             [--save-debugging-info=<debug-filename>]
             [--save-obfuscation-map=<map-filename>]
             <dart-kernel-file>

             AOT snapshots can be obfuscated: that is all identifiers will be renamed
             during compilation. This mode is enabled with --obfuscate flag. Mapping
             between original and obfuscated names can be serialized as a JSON array
             using --save-obfuscation-map=<filename> option. See dartbug.com/30524
             for implementation details and limitations of the obfuscation pass.
  [  +12 ms] java -version
  [ +100 ms] executing: /home/user/Android/Sdk/cmdline-tools/latest/bin/sdkmanager --licenses
  [+5491 ms] executing: /home/user/Android/Sdk/platform-tools/adb devices -l
  [ +379 ms] List of devices attached

                      * daemon not running; starting now at tcp:5037
                      * daemon started successfully
  [   +9 ms] executing: /home/user/Android/Sdk/platform-tools/adb devices -l
  [  +13 ms] List of devices attached
  [   +4 ms] [✓] Flutter: is fully installed. (Channel dev, 1.21.0-1.0.pre, on Linux, locale en_IN)
             [✓] Android toolchain - develop for Android devices: is fully installed. (Android SDK version 30.0.1)
             [✓] Android Studio: is fully installed. (version 4.0)
             [✓] VS Code: is fully installed. (version 1.47.2)
             [!] Connected device: is not available.

             Run "flutter doctor" for information about installing additional components.

  [   +1 ms] In order to run your application, type:

               $ cd testapp_dev_boot_1
               $ flutter run

             Your application code is in testapp_dev_boot_1/lib/main.dart.

  [   +3 ms] "flutter create" took 13,524ms.
  [ +270 ms] ensureAnalyticsSent: 255ms
  [   +4 ms] Running shutdown hooks
  [        ] Shutdown hooks complete
  [        ] exiting with code 0
  user@user-Latitude-3500:~/flutter_projects$
  user@user-Latitude-3500:~/flutter_projects$
  user@user-Latitude-3500:~/flutter_projects$
  user@user-Latitude-3500:~/flutter_projects$
  user@user-Latitude-3500:~/flutter_projects$
  user@user-Latitude-3500:~/flutter_projects$
  user@user-Latitude-3500:~/flutter_projects$ flutter doctor
  Doctor summary (to see all details, run flutter doctor -v):
  [✓] Flutter (Channel dev, 1.21.0-1.0.pre, on Linux, locale en_IN)
  [✓] Android toolchain - develop for Android devices (Android SDK version 30.0.1)
  [✓] Android Studio (version 4.0)
  [✓] VS Code (version 1.47.2)
  [!] Connected device
      ! No devices available

  ! Doctor found issues in 1 category.
  user@user-Latitude-3500:~/flutter_projects$
  user@user-Latitude-3500:~/flutter_projects$
  user@user-Latitude-3500:~/flutter_projects$
  user@user-Latitude-3500:~/flutter_projects$
  user@user-Latitude-3500:~/flutter_projects$

@nvmav your comment "I was using Wi-Fi network at home in India." is what solved it for me.  I too am in India and was suddenly running into the same issues.  I've been troubleshooting for hours.   The FIX...sping up my VPN and connect from the US.
We must be tripping some security flags on "https://pub.dartlang.org/".
Temp Solution:  Use VPN