NoSuchMethodError: The getter 'flow' was called on null

[yuchuan08]

Thank you for taking the time to file an issue!

Doctor summary (to see all details, run flutter doctor -v):
[✓] Flutter (Channel stable, 2.0.0, on macOS 11.6 20G165 darwin-x64, locale zh-Hans-CN)
[✓] Android toolchain - develop for Android devices (Android SDK version 30.0.3)
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[✓] Android Studio (version 4.2)

When I input flutter packages pub run build_runner build --delete-conflicting-outputs，the error is：

NoSuchMethodError: The getter 'flow' was called on null.
Receiver: null
Tried calling: flow
#0 Object.noSuchMethod (dart:core-patch/object_patch.dart:54:5)
dart-lang/build#1 ResolverVisitor.startNullAwarePropertyAccess (package:analyzer/src/generated/resolver.dart:805:23)
dart-lang/build#2 ResolverVisitor.visitPropertyAccess (package:analyzer/src/generated/resolver.dart:1776:5)
dart-lang/build#3 PropertyAccessImpl.accept (package:analyzer/src/dart/ast/ast.dart:8390:49)
dart-lang/build#4 BinaryExpressionResolver._resolveEqual (package:analyzer/src/dart/resolver/binary_expression_resolver.dart:111:10)
dart-lang/build#5 BinaryExpressionResolver.resolve (package:analyzer/src/dart/resolver/binary_expression_resolver.dart:58:7)
dart-lang/build#6 ResolverVisitor.visitBinaryExpression (package:analyzer/src/generated/resolver.dart:944:31)
dart-lang/build#7 BinaryExpressionImpl.accept (package:analyzer/src/dart/ast/ast.dart:956:49)
dart-lang/build#8 BinaryExpressionResolver._resolveLogicalOr (package:analyzer/src/dart/resolver/binary_expression_resolver.dart:224:11)
dart-lang/build#9 BinaryExpressionResolver.resolve (package:analyzer/src/dart/resolver/binary_expression_resolver.dart:63:7)
dart-lang/build#10 ResolverVisitor.visitBinaryExpression (package:analyzer/src/generated/resolver.dart:944:31)
dart-lang/build#11 BinaryExpressionImpl.accept (package:analyzer/src/dart/ast/ast.dart:956:49)
dart-lang/build#12 ResolverVisitor.visitAssertInitializer (package:analyzer/src/generated/resolver.dart:903:21)
dart-lang/build#13 AssertInitializerImpl.accept (package:analyzer/src/dart/ast/ast.dart:519:49)
dart-lang/build#14 AstResolver.resolve (package:analyzer/src/summary2/ast_resolver.dart:85:10)
dart-lang/build#15 ConstructorInitializerResolver._initializers (package:analyzer/src/summary2/constructor_initializer_resolver.dart:68:20)
dart-lang/build#16 ConstructorInitializerResolver._constructor (package:analyzer/src/summary2/constructor_initializer_resolver.dart:54:5)
dart-lang/build#17 ConstructorInitializerResolver.resolve (package:analyzer/src/summary2/constructor_initializer_resolver.dart:31:11)
dart-lang/build#18 LibraryBuilder.resolveConstructors (package:analyzer/src/summary2/library_builder.dart:240:53)
dart-lang/build#19 Linker._resolveConstructors (package:analyzer/src/summary2/link.dart:210:15)
dart-lang/build#20 Linker._buildOutlines (package:analyzer/src/summary2/link.dart:95:5)
dart-lang/build#21 Linker.link (package:analyzer/src/summary2/link.dart:76:5)
dart-lang/build#22 link (package:analyzer/src/summary2/link.dart:32:10)
dart-lang/build#23 LibraryContext.load2.loadBundle (package:analyzer/src/dart/analysis/library_context.dart:215:24)
dart-lang/build#24 LibraryContext.load2.loadBundle. (package:analyzer/src/dart/analysis/library_context.dart:123:26)
dart-lang/build#25 SetMixin.forEach (dart:collection/set.dart:142:30)
dart-lang/build#26 LibraryContext.load2.loadBundle (package:analyzer/src/dart/analysis/library_context.dart:122:32)
dart-lang/build#27 LibraryContext.load2.loadBundle. (package:analyzer/src/dart/analysis/library_context.dart:123:26)
dart-lang/build#28 SetMixin.forEach (dart:collection/set.dart:142:30)
dart-lang/build#29 LibraryContext.load2.loadBundle (package:analyzer/src/dart/analysis/library_context.dart:122:32)
dart-lang/build#30 LibraryContext.load2. (package:analyzer/src/dart/analysis/library_context.dart:262:17)
dart-lang/build#31 PerformanceLog.run (package:analyzer/src/dart/analysis/performance_logger.dart:32:15)
dart-lang/build#32 LibraryContext.load2 (package:analyzer/src/dart/analysis/library_context.dart:260:12)
dart-lang/build#33 new LibraryContext (package:analyzer/src/dart/analysis/library_context.dart:77:5)
dart-lang/build#34 AnalysisDriver._createLibraryContext. (package:analyzer/src/dart/analysis/driver.dart:1538:27)
dart-lang/build#35 _rootRun (dart:async/zone.dart:1354:13)
dart-lang/build#36 _CustomZone.run (dart:async/zone.dart:1258:19)
dart-lang/build#37 _runZoned (dart:async/zone.dart:1788:10)
dart-lang/build#38 runZoned (dart:async/zone.dart:1710:10)
dart-lang/build#39 NullSafetyUnderstandingFlag.enableNullSafetyTypes (package:analyzer/dart/element/null_safety_understanding_flag.dart:42:12)
dart-lang/build#40 AnalysisDriver._createLibraryContext (package:analyzer/src/dart/analysis/driver.dart:1536:33)
dart-lang/build#41 AnalysisDriver._computeUnitElement. (package:analyzer/src/dart/analysis/driver.dart:1464:28)
dart-lang/build#42 PerformanceLog.run (package:analyzer/src/dart/analysis/performance_logger.dart:32:15)
dart-lang/build#43 AnalysisDriver._computeUnitElement (package:analyzer/src/dart/analysis/driver.dart:1462:20)
dart-lang/build#44 AnalysisDriver.performWork (package:analyzer/src/dart/analysis/driver.dart:1020:34)
dart-lang/build#45 AnalysisDriverScheduler._run (package:analyzer/src/dart/analysis/driver.dart:2013:24)

[jakemac53]

Moved to the sdk as this looks like an analyzer issue

[yuchuan08]

@jakemac53
Hello，change flutter stable 2.2.3，the error same。Can you help me solve this problem？

[srawlins]

@yuchuan08 is the code which triggers this crash open source? Can you perhaps link us to the code which crashes, or perhaps create and paste a minimal reproduction which causes this crash?

[srawlins]

Thanks for upgrading Flutter. Flutter 2.2.3 is still not super recent; flutter 2.5.x is available. You also might try pub upgrade to get the latest version of the analyzer package, which is where the crash is taking place.

[srawlins]

Please re-open if you see this problem again.