Dart Null-Safety - 执行 dart migrate 以升级到新的 null 安全时出现范围错误

Question

我在将自定义包升级到空安全时遇到问题，并且在此处和任何其他平台上搜索时没有找到任何解决方案，甚至没有找到相同的问题。

在为 Flutter 2.0 空安全升级自定义包时，我按照指南的建议使用了dart migrate ，但出现编译器错误。

但是错误没有指定它发生的位置，错误描述也没有任何帮助。 我查看了整个包以找到任何数组/列表或包含范围错误，但没有任何成功。

我没有任何想法来修复此错误并完成对空安全的升级。 有人知道我可以尝试修复此错误吗？

错误信息：

dart migrate           
Migrating file_name

See https://dart.dev/go/null-safety-migration for a migration guide.

Note: more than one project found; migrating the top-level project.

Analyzing project...
[--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------]No analysis issues found.

Generating migration suggestions...
[--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------]

Compiling instrumentation information...
[--------------------|                                                                                                                                                                 ]RangeError (index): Invalid value: Not in inclusive range 0..12: 13
#0      List.[] (dart:core-patch/array.dart:268:52)
#1      BestPracticesVerifier._targetKindsFor (package:analyzer/src/error/best_practices_verifier.dart:1582:38)
#2      BestPracticesVerifier.visitAnnotation (package:analyzer/src/error/best_practices_verifier.dart:250:17)
#3      AnnotationImpl.accept (package:analyzer/src/dart/ast/ast.dart:280:49)
#4      NodeListImpl.accept (package:analyzer/src/dart/ast/ast.dart:7611:20)
#5      AnnotatedNodeImpl.visitChildren (package:analyzer/src/dart/ast/ast.dart:148:17)
#6      ClassDeclarationImpl.visitChildren (package:analyzer/src/dart/ast/ast.dart:1559:11)
#7      RecursiveAstVisitor.visitClassDeclaration (package:analyzer/dart/ast/visitor.dart:707:10)
#8      BestPracticesVerifier.visitClassDeclaration (package:analyzer/src/error/best_practices_verifier.dart:320:13)
#9      ClassDeclarationImpl.accept (package:analyzer/src/dart/ast/ast.dart:1536:49)
#10     NodeListImpl.accept (package:analyzer/src/dart/ast/ast.dart:7611:20)
#11     CompilationUnitImpl.visitChildren (package:analyzer/src/dart/ast/ast.dart:2141:21)
#12     RecursiveAstVisitor.visitCompilationUnit (package:analyzer/dart/ast/visitor.dart:731:10)
#13     CompilationUnitImpl.accept (package:analyzer/src/dart/ast/ast.dart:2134:49)
#14     LibraryAnalyzer._computeHints (package:analyzer/src/dart/analysis/library_analyzer.dart:281:10)
#15     LibraryAnalyzer.analyzeSync.<anonymous closure> (package:analyzer/src/dart/analysis/library_analyzer.dart:167:9)
#16     _LinkedHashMapMixin.forEach (dart:collection-patch/compact_hash.dart:397:8)
#17     LibraryAnalyzer.analyzeSync (package:analyzer/src/dart/analysis/library_analyzer.dart:166:13)
#18     LibraryAnalyzer.analyze (package:analyzer/src/dart/analysis/library_analyzer.dart:107:12)
#19     AnalysisDriver._computeResolvedLibrary2.<anonymous closure> (package:analyzer/src/dart/analysis/driver.dart:1416:65)
#20     PerformanceLog.run (package:analyzer/src/dart/analysis/performance_logger.dart:32:15)
#21     AnalysisDriver._computeResolvedLibrary2 (package:analyzer/src/dart/analysis/driver.dart:1402:20)
#22     AnalysisDriver._computeResolvedLibrary.<anonymous closure> (package:analyzer/src/dart/analysis/driver.dart:1395:15)
#23     _rootRun (dart:async/zone.dart:1354:13)
#24     _CustomZone.run (dart:async/zone.dart:1258:19)
#25     _runZoned (dart:async/zone.dart:1788:10)
#26     runZoned (dart:async/zone.dart:1710:10)
#27     NullSafetyUnderstandingFlag.enableNullSafetyTypes (package:analyzer/dart/element/null_safety_understanding_flag.dart:42:12)
#28     AnalysisDriver._computeResolvedLibrary (package:analyzer/src/dart/analysis/driver.dart:1394:40)
#29     AnalysisDriver.performWork (package:analyzer/src/dart/analysis/driver.dart:964:22)
#30     AnalysisDriverScheduler._run (package:analyzer/src/dart/analysis/driver.dart:2018:24)
<asynchronous suspension>

Answer 1

这似乎是 Dart SDK 本身的一个错误。 这在dart-lang/sdk#46183 中进行了跟踪，并在此提交中得到了修复。

试用步骤：

1. 运行flutter upgrade以确保您使用的是最新版本。
2. 如果此后您仍然遇到问题，请考虑更改为 Flutter 的beta通道以获得更前沿的 SDK 以运行迁移工具，然后在完成后切换回stable通道。 您可以通过运行flutter channel beta ，然后重新运行迁移，然后flutter channel stable切换回来。

Answer 2

我遇到了同样的问题，如 cbracken 的回答中所述，它已在 beta 频道中修复。

另外，就我而言，我在 Flutter 之外安装了第二个 Dart SDK (2.12)，所以问题似乎没有解决。

确保您正在使用 Flutter SDK Flutter/bin文件夹中包含的dart migrate运行dart migrate 。