我一直在尝试在 Windows 上为我的 Flutter 项目获取依赖项，但这需要很长时间，过了一会儿，它会在“消息”栏中显示此错误。
Running "flutter pub get" in badhan_blood_bank...
OS Error: The semaphore timeout period has expired.
, errno = 121, address = storage.googleapis.com, port = 53515
pub get failed (server unavailable) -- attempting retry 1 in 1 second...
我试图以某种方式解决这个问题，但未能解决。我正在做flutter clean，flutter升级并在最后重新启动android studio，同样的问题发生了。
在我在项目的依赖项中添加 url_launcher 之前它工作正常。
这是我的 pubspec.yaml 文件：
version: 1.0.0+1
environment:
sdk: ">=2.1.0 <3.0.0"
dependencies:
flutter:
sdk: flutter
cupertino_icons: ^0.1.2
firebase_auth: ^0.15.5+2
flutter_facebook_login: ^3.0.0
flutter_icons: ^1.0.0+1
flutter_spinkit: ^4.1.2
firebase_database: ^3.1.3
google_maps_flutter: ^0.5.25
geolocator: ^5.3.0
intl: ^0.16.1
curved_navigation_bar: ^0.3.2
fluttertoast: ^4.0.1
url_launcher: ^5.4.2
dev_dependencies:
flutter_test:
sdk: flutter
flutter:
uses-material-design: true
assets:
- images/
运行“flutter pub get --verbose”后显示：
[ +27 ms] executing: [C:\src\flutter\flutter\] git -c log.showSignature=false log -n 1 --pretty=format:%H
[ +64 ms] Exit code 0 from: git -c log.showSignature=false log -n 1 --pretty=format:%H
[ ] 0b8abb4724aa590dd0f429683339b1e045a1594d
[ ] executing: [C:\src\flutter\flutter\] git describe --match v*.*.* --first-parent --long --tags
[ +56 ms] Exit code 0 from: git describe --match v*.*.* --first-parent --long --tags
[ ] v1.12.13+hotfix.8-0-g0b8abb472
[ +7 ms] executing: [C:\src\flutter\flutter\] git rev-parse --abbrev-ref --symbolic @{u}
[ +41 ms] Exit code 0 from: git rev-parse --abbrev-ref --symbolic @{u}
[ ] origin/stable
[ ] executing: [C:\src\flutter\flutter\] git ls-remote --get-url origin
[ +38 ms] Exit code 0 from: git ls-remote --get-url origin
[ ] https://github.com/flutter/flutter.git
[ +77 ms] executing: [C:\src\flutter\flutter\] git rev-parse --abbrev-ref HEAD
[ +41 ms] Exit code 0 from: git rev-parse --abbrev-ref HEAD
[ ] stable
[ +48 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.
[ +4 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.
[ +130 ms] Running "flutter pub get" in badhan_blood_bank...
[ +5 ms] Using C:\src\flutter\flutter\.pub-cache for the pub cache.
[ +1 ms] executing: [D:\@@MyWorks\mahmud\Badhan Blood Bank\badhan_blood_bank\] C:\src\flutter\flutter\bin\cache\dart-sdk\bin\pub.bat --verbose get
--no-precompile
[ +157 ms] FINE: Pub 2.7.0
[ +3 ms] IO : Spawning "cmd /c ver" in D:\@@MyWorks\mahmud\Badhan Blood Bank\badhan_blood_bank\.
[ +7 ms] IO : Finished ver. Exit code 0.
[ +1 ms] | stdout:
[ ] | |
[ +1 ms] | | Microsoft Windows [Version 10.0.18362.720]
[ +1 ms] | Nothing output on stderr.
[ +102 ms] MSG : Resolving dependencies...
[ +9 ms] SLVR: fact: badhanbloodbank is 1.0.0+1
[ +5 ms] SLVR: derived: badhanbloodbank
[ +61 ms] SLVR: fact: badhanbloodbank depends on flutter any from sdk
[ +1 ms] SLVR: fact: badhanbloodbank depends on cupertino_icons ^0.1.2
[ +1 ms] SLVR: fact: badhanbloodbank depends on firebase_auth ^0.15.5+2
[ +1 ms] SLVR: fact: badhanbloodbank depends on flutter_facebook_login ^3.0.0
[ +1 ms] SLVR: fact: badhanbloodbank depends on flutter_icons ^1.0.0+1
[ +1 ms] SLVR: fact: badhanbloodbank depends on flutter_spinkit ^4.1.2
[ ] SLVR: fact: badhanbloodbank depends on firebase_database ^3.1.3
[ ] SLVR: fact: badhanbloodbank depends on google_maps_flutter ^0.5.25
[ ] SLVR: fact: badhanbloodbank depends on geolocator ^5.3.0
[ ] SLVR: fact: badhanbloodbank depends on intl ^0.16.1
[ ] SLVR: fact: badhanbloodbank depends on curved_navigation_bar ^0.3.2
[ ] SLVR: fact: badhanbloodbank depends on fluttertoast ^4.0.1
[ ] SLVR: fact: badhanbloodbank depends on url_launcher ^5.4.2
[ ] SLVR: fact: badhanbloodbank depends on flutter_test any from sdk
[ ] SLVR: selecting badhanbloodbank
[ ] SLVR: derived: flutter_test any from sdk
[ ] SLVR: derived: url_launcher ^5.4.2
[ +1 ms] SLVR: derived: fluttertoast ^4.0.1
[ +1 ms] SLVR: derived: curved_navigation_bar ^0.3.2
[ ] SLVR: derived: intl ^0.16.1
[ +1 ms] SLVR: derived: geolocator ^5.3.0
[ +1 ms] SLVR: derived: google_maps_flutter ^0.5.25
[ +1 ms] SLVR: derived: firebase_database ^3.1.3
[ ] SLVR: derived: flutter_spinkit ^4.1.2
[ ] SLVR: derived: flutter_icons ^1.0.0+1
[ ] SLVR: derived: flutter_facebook_login ^3.0.0
[ ] SLVR: derived: firebase_auth ^0.15.5+2
[ ] SLVR: derived: cupertino_icons ^0.1.2
[ ] SLVR: derived: flutter any from sdk
[ ] IO : Get versions from https://pub.dartlang.org/api/packages/url_launcher.
[ +9 ms] IO : HTTP GET https://pub.dartlang.org/api/packages/url_launcher
[ +2 ms] | Accept: application/vnd.pub.v2+json
[ +1 ms] | X-Pub-OS: windows
[ ] | X-Pub-Command: get
[ ] | X-Pub-Session-ID: 795584D9-523C-4575-B686-2D496C324C5B
[ ] | X-Pub-Environment: flutter_cli:get
[ +1 ms] | X-Pub-Reason: direct
[ ] | user-agent: Dart pub 2.7.0
[ +934 ms] IO : HTTP response 200 OK for GET https://pub.dartlang.org/api/packages/url_launcher
[ +5 ms] | took 0:00:00.938247
[ +2 ms] | transfer-encoding: chunked
[ +2 ms] | date: Sun, 29 Mar 2020 19:47:07 GMT
[ +2 ms] | content-encoding: gzip
[ +2 ms] | vary: Accept-Encoding
[ +3 ms] | strict-transport-security: max-age=31536000; preload
[ +3 ms] | via: 1.1 google
[ +2 ms] | content-type: application/json
[ +2 ms] | x-frame-options: SAMEORIGIN
[ +2 ms] | x-xss-protection: 1; mode=block
[ +2 ms] | x-content-type-options: nosniff
[ +2 ms] | server: dart:io with Shelf
[ +66 ms] SLVR: fact: flutter_test 0.0.0 from sdk depends on flutter any from sdk
[ +1 ms] SLVR: fact: flutter_test 0.0.0 from sdk depends on test_api 0.2.11
[ ] SLVR: fact: flutter_test 0.0.0 from sdk depends on path 1.6.4
[ ] SLVR: fact: flutter_test 0.0.0 from sdk depends on image 2.1.4
[ ] SLVR: fact: flutter_test 0.0.0 from sdk depends on quiver 2.0.5
[ +1 ms] SLVR: fact: flutter_test 0.0.0 from sdk depends on stack_trace 1.9.3
[ ] SLVR: fact: flutter_test 0.0.0 from sdk depends on vector_math 2.0.8
[ ] SLVR: fact: flutter_test 0.0.0 from sdk depends on archive 2.0.11
[ ] SLVR: fact: flutter_test 0.0.0 from sdk depends on args 1.5.2
[ +1 ms] SLVR: fact: flutter_test 0.0.0 from sdk depends on async 2.4.0
[ +1 ms] SLVR: fact: flutter_test 0.0.0 from sdk depends on boolean_selector 1.0.5
[ ] SLVR: fact: flutter_test 0.0.0 from sdk depends on charcode 1.1.2
[ +1 ms] SLVR: fact: flutter_test 0.0.0 from sdk depends on collection 1.14.11
[ +1 ms] SLVR: fact: flutter_test 0.0.0 from sdk depends on convert 2.1.1
[ ] SLVR: fact: flutter_test 0.0.0 from sdk depends on crypto 2.1.3
[ ] SLVR: fact: flutter_test 0.0.0 from sdk depends on matcher 0.12.6
[ +2 ms] SLVR: fact: flutter_test 0.0.0 from sdk depends on meta 1.1.8
[ ] SLVR: fact: flutter_test 0.0.0 from sdk depends on pedantic 1.8.0+1
[ ] SLVR: fact: flutter_test 0.0.0 from sdk depends on petitparser 2.4.0
[ ] SLVR: fact: flutter_test 0.0.0 from sdk depends on source_span 1.5.5
[ ] SLVR: fact: flutter_test 0.0.0 from sdk depends on stream_channel 2.0.0
[ ] SLVR: fact: flutter_test 0.0.0 from sdk depends on string_scanner 1.0.5
[ ] SLVR: fact: flutter_test 0.0.0 from sdk depends on term_glyph 1.1.0
[ ] SLVR: fact: flutter_test 0.0.0 from sdk depends on typed_data 1.1.6
[ +1 ms] SLVR: fact: flutter_test 0.0.0 from sdk depends on xml 3.5.0
[ ] SLVR: selecting flutter_test 0.0.0 from sdk
[ ] SLVR: derived: xml 3.5.0
[ ] SLVR: derived: typed_data 1.1.6
[ +1 ms] SLVR: derived: term_glyph 1.1.0
[ ] SLVR: derived: string_scanner 1.0.5
[ ] SLVR: derived: stream_channel 2.0.0
[ +2 ms] SLVR: derived: source_span 1.5.5
[ ] SLVR: derived: petitparser 2.4.0
[ ] SLVR: derived: pedantic 1.8.0+1
[ ] SLVR: derived: meta 1.1.8
[ +3 ms] SLVR: derived: matcher 0.12.6
[ ] SLVR: derived: crypto 2.1.3
[ ] SLVR: derived: convert 2.1.1
[ +1 ms] SLVR: derived: collection 1.14.11
[ ] SLVR: derived: charcode 1.1.2
[ ] SLVR: derived: boolean_selector 1.0.5
[ ] SLVR: derived: async 2.4.0
[ +1 ms] SLVR: derived: args 1.5.2
[ +4 ms] SLVR: derived: archive 2.0.11
[ +1 ms] SLVR: derived: vector_math 2.0.8
[ +4 ms] SLVR: derived: stack_trace 1.9.3
[ +1 ms] SLVR: derived: quiver 2.0.5
[ ] SLVR: derived: image 2.1.4
[ +1 ms] SLVR: derived: path 1.6.4
[ +1 ms] SLVR: derived: test_api 0.2.11
[ +1 ms] SLVR: fact: url_launcher >=3.0.0 depends on flutter any from sdk
[ ] SLVR: fact: url_launcher >=5.4.0 depends on url_launcher_macos ^0.0.1
[ +1 ms] SLVR: fact: url_launcher >=5.4.1 depends on url_launcher_platform_interface ^1.0.4
[ +1 ms] SLVR: fact: url_launcher >=5.3.0 depends on url_launcher_web ^0.1.0+1
[ +1 ms] SLVR: selecting url_launcher 5.4.2
[ ] SLVR: derived: url_launcher_web ^0.1.0+1
[ ] SLVR: derived: url_launcher_platform_interface ^1.0.4
[ ] SLVR: derived: url_launcher_macos ^0.0.1
[ +1 ms] IO : Get versions from https://pub.dartlang.org/api/packages/url_launcher_web.
[ +1 ms] IO : HTTP GET https://pub.dartlang.org/api/packages/url_launcher_web
[ ] | Accept: application/vnd.pub.v2+json
[ ] | X-Pub-OS: windows
[ ] | X-Pub-Command: get
[ ] | X-Pub-Session-ID: 795584D9-523C-4575-B686-2D496C324C5B
[ ] | X-Pub-Environment: flutter_cli:get
[ ] | user-agent: Dart pub 2.7.0
[ +429 ms] IO : HTTP response 200 OK for GET https://pub.dartlang.org/api/packages/url_launcher_web
问题是什么以及如何解决？