Possible bug in the null migration tool

[szakarias]

Dart SDK version (2.15.0-154.0.dev)

Exception details:

Never.substitute(Never | {T: int?(type argument 0 of supertype of PubCommand (command.dart:48:43))}) at offset 3428 in /usr/local/google/home/zarah/pub/lib/src/command/add.dart (usageException('Must specify a package to be added.'))

#0 DecoratedType._substitute (package:nnbd_migration/src/decorated_type.dart:468:5)
#1 DecoratedType._substituteFunctionAfterFormals (package:nnbd_migration/src/decorated_type.dart:496:25)
#2 DecoratedType._substitute (package:nnbd_migration/src/decorated_type.dart:447:14)
#3 DecoratedType.substitute (package:nnbd_migration/src/decorated_type.dart:328:12)
#4 EdgeBuilder.getOrComputeElementType (package:nnbd_migration/src/edge_builder.dart:365:32)
#5 EdgeBuilder.visitMethodInvocation (package:nnbd_migration/src/edge_builder.dart:1368:20)
#6 MethodInvocationImpl.accept (package:analyzer/src/dart/ast/ast.dart:7193:50)
#7 EdgeBuilder._dispatch (package:nnbd_migration/src/edge_builder.dart:2305:24)
#8 EdgeBuilder.visitExpressionStatement (package:nnbd_migration/src/edge_builder.dart:879:25)
#9 ExpressionStatementImpl.accept (package:analyzer/src/dart/ast/ast.dart:3623:50)
#10 EdgeBuilder._dispatch (package:nnbd_migration/src/edge_builder.dart:2305:24)
#11 EdgeBuilder.visitNode (package:nnbd_migration/src/edge_builder.dart:1501:9)
#12 GeneralizingAstVisitor.visitStatement (package:analyzer/dart/ast/visitor.dart:545:40)
#13 GeneralizingAstVisitor.visitBlock (package:analyzer/dart/ast/visitor.dart:165:32)
#14 BlockImpl.accept (package:analyzer/src/dart/ast/ast.dart:1046:50)
#15 EdgeBuilder._dispatch (package:nnbd_migration/src/edge_builder.dart:2305:24)
#16 EdgeBuilder.visitIfStatement. (package:nnbd_migration/src/edge_builder.dart:1120:25)
#17 ScopedSet.doScoped (package:nnbd_migration/src/utilities/scoped_set.dart:44:13)
#18 EdgeBuilder.visitIfStatement (package:nnbd_migration/src/edge_builder.dart:1119:28)
#19 IfStatementImpl.accept (package:analyzer/src/dart/ast/ast.dart:5751:50)
#20 EdgeBuilder._dispatch (package:nnbd_migration/src/edge_builder.dart:2305:24)
#21 EdgeBuilder.visitNode (package:nnbd_migration/src/edge_builder.dart:1501:9)
#22 GeneralizingAstVisitor.visitStatement (package:analyzer/dart/ast/visitor.dart:545:40)
#23 GeneralizingAstVisitor.visitBlock (package:analyzer/dart/ast/visitor.dart:165:32)
#24 BlockImpl.accept (package:analyzer/src/dart/ast/ast.dart:1046:50)
#25 EdgeBuilder._dispatch (package:nnbd_migration/src/edge_builder.dart:2305:24)
#26 EdgeBuilder.visitNode (package:nnbd_migration/src/edge_builder.dart:1501:9)
#27 GeneralizingAstVisitor.visitFunctionBody (package:analyzer/dart/ast/visitor.dart:330:46)
#28 GeneralizingAstVisitor.visitBlockFunctionBody (package:analyzer/dart/ast/visitor.dart:168:56)
#29 BlockFunctionBodyImpl.accept (package:analyzer/src/dart/ast/ast.dart:1001:50)
#30 EdgeBuilder._dispatch (package:nnbd_migration/src/edge_builder.dart:2305:24)
#31 EdgeBuilder._handleExecutableDeclaration (package:nnbd_migration/src/edge_builder.dart:2603:7)
#32 EdgeBuilder.visitMethodDeclaration (package:nnbd_migration/src/edge_builder.dart:1327:5)
#33 MethodDeclarationImpl.accept (package:analyzer/src/dart/ast/ast.dart:7046:50)
#34 EdgeBuilder._dispatch (package:nnbd_migration/src/edge_builder.dart:2305:24)
#35 EdgeBuilder._dispatchList (package:nnbd_migration/src/edge_builder.dart:2323:7)
#36 EdgeBuilder.visitClassOrMixinOrExtensionDeclaration (package:nnbd_migration/src/edge_builder.dart:674:7)
#37 EdgeBuilder.visitClassDeclaration (package:nnbd_migration/src/edge_builder.dart:641:5)
#38 ClassDeclarationImpl.accept (package:analyzer/src/dart/ast/ast.dart:1487:50)
#39 EdgeBuilder._dispatch (package:nnbd_migration/src/edge_builder.dart:2305:24)
#40 EdgeBuilder.visitNode (package:nnbd_migration/src/edge_builder.dart:1501:9)
#41 GeneralizingAstVisitor.visitCompilationUnit (package:analyzer/dart/ast/visitor.dart:202:52)
#42 CompletenessTracker.visitCompilationUnit. (package:nnbd_migration/src/utilities/completeness_tracker.dart:52:24)
#43 PermissiveModeVisitor.reportExceptionsIfPermissive (package:nnbd_migration/src/utilities/permissive_mode.dart:26:24)
#44 CompletenessTracker.visitCompilationUnit (package:nnbd_migration/src/utilities/completeness_tracker.dart:43:5)
#45 CompilationUnitImpl.accept (package:analyzer/src/dart/ast/ast.dart:2076:50)
#46 NullabilityMigrationImpl.processInput (package:nnbd_migration/src/nullability_migration_impl.dart:231:12)
#47 NonNullableFix.processUnit (package:nnbd_migration/src/front_end/non_nullable_fix.dart:164:16)
#48 _FixCodeProcessor.runLaterPhases. (package:nnbd_migration/migration_cli.dart:1092:20)
#49 _FixCodeProcessor.runLaterPhases. (package:nnbd_migration/migration_cli.dart:1090:28)
#50 _FixCodeProcessor.processResources (package:nnbd_migration/migration_cli.dart:1024:26)

#51 _FixCodeProcessor.runLaterPhases (package:nnbd_migration/migration_cli.dart:1090:5)

#52 MigrationCliRunner.run (package:nnbd_migration/migration_cli.dart:697:24)

#53 MigrateCommand.run (package:dartdev/src/commands/migrate.dart:37:7)

#54 CommandRunner.runCommand (package:args/command_runner.dart:209:13)

#55 DartdevRunner.runCommand (package:dartdev/dartdev.dart:223:18)

#56 runDartdev (package:dartdev/dartdev.dart:66:16)

#57 main (file:///b/s/w/ir/cache/builder/sdk/pkg/dartdev/bin/dartdev.dart:11:3)

[robbecker-wf]

I am also seeing this same exception when running the migration tool. The good news is it's reproducible in a public repo https://github.com/Workiva/webdev_proxy. This happens with Dart versions of 2.12.4 up to 2.18.7.

I suspect it may have to do with the version of analyzer? The project recently had dependencies updated to allow analyzer version >= 1. In webdev_proxy 0.1.7 analyzer resolved to 0.41.2 and in 0.1.8 and master it resolves to 1.7.2.

Never.substitute(Never | {T: int?(type argument 0 of supertype of ServeCommand (serve_command.dart:35:36))}) at offset 3969 in /Users/robbecker/code/webdev_proxy/lib/src/serve_command.dart (usageException)

#0      DecoratedType._substitute (package:nnbd_migration/src/decorated_type.dart:472:5)
#1      DecoratedType._substituteFunctionAfterFormals (package:nnbd_migration/src/decorated_type.dart:500:25)
#2      DecoratedType._substitute (package:nnbd_migration/src/decorated_type.dart:451:14)
#3      DecoratedType.substitute (package:nnbd_migration/src/decorated_type.dart:332:12)
#4      EdgeBuilder.getOrComputeElementType (package:nnbd_migration/src/edge_builder.dart:378:32)
#5      EdgeBuilder.visitSimpleIdentifier (package:nnbd_migration/src/edge_builder.dart:1801:11)
#6      SimpleIdentifierImpl.accept (package:analyzer/src/dart/ast/ast.dart:9867:50)
#7      EdgeBuilder._dispatch (package:nnbd_migration/src/edge_builder.dart:2341:24)
#8      EdgeBuilder._handleAssignment (package:nnbd_migration/src/edge_builder.dart:2470:20)
#9      EdgeBuilder._handleInvocationArguments (package:nnbd_migration/src/edge_builder.dart:3086:7)
#10     EdgeBuilder.visitMethodInvocation (package:nnbd_migration/src/edge_builder.dart:1417:24)
#11     MethodInvocationImpl.accept (package:analyzer/src/dart/ast/ast.dart:7912:50)
#12     EdgeBuilder._dispatch (package:nnbd_migration/src/edge_builder.dart:2341:24)
#13     EdgeBuilder.visitExpressionStatement (package:nnbd_migration/src/edge_builder.dart:895:25)
#14     ExpressionStatementImpl.accept (package:analyzer/src/dart/ast/ast.dart:4065:50)
#15     EdgeBuilder._dispatch (package:nnbd_migration/src/edge_builder.dart:2341:24)
#16     EdgeBuilder.visitNode (package:nnbd_migration/src/edge_builder.dart:1537:9)
#17     GeneralizingAstVisitor.visitStatement (package:analyzer/dart/ast/visitor.dart:560:40)
#18     GeneralizingAstVisitor.visitBlock (package:analyzer/dart/ast/visitor.dart:167:32)
#19     BlockImpl.accept (package:analyzer/src/dart/ast/ast.dart:1183:50)
#20     EdgeBuilder._dispatch (package:nnbd_migration/src/edge_builder.dart:2341:24)
#21     EdgeBuilder.visitNode (package:nnbd_migration/src/edge_builder.dart:1537:9)
#22     GeneralizingAstVisitor.visitFunctionBody (package:analyzer/dart/ast/visitor.dart:338:46)
#23     GeneralizingAstVisitor.visitBlockFunctionBody (package:analyzer/dart/ast/visitor.dart:170:56)
#24     BlockFunctionBodyImpl.accept (package:analyzer/src/dart/ast/ast.dart:1134:50)
#25     EdgeBuilder._dispatch (package:nnbd_migration/src/edge_builder.dart:2341:24)
#26     EdgeBuilder._handleExecutableDeclaration (package:nnbd_migration/src/edge_builder.dart:2637:7)
#27     EdgeBuilder.visitMethodDeclaration (package:nnbd_migration/src/edge_builder.dart:1363:5)
#28     MethodDeclarationImpl.accept (package:analyzer/src/dart/ast/ast.dart:7764:50)
#29     EdgeBuilder._dispatch (package:nnbd_migration/src/edge_builder.dart:2341:24)
#30     EdgeBuilder._dispatchList (package:nnbd_migration/src/edge_builder.dart:2359:7)
#31     EdgeBuilder.visitClassOrMixinOrExtensionDeclaration (package:nnbd_migration/src/edge_builder.dart:690:7)
#32     EdgeBuilder.visitClassDeclaration (package:nnbd_migration/src/edge_builder.dart:657:5)
#33     ClassDeclarationImpl.accept (package:analyzer/src/dart/ast/ast.dart:1698:50)
#34     EdgeBuilder._dispatch (package:nnbd_migration/src/edge_builder.dart:2341:24)
#35     EdgeBuilder.visitNode (package:nnbd_migration/src/edge_builder.dart:1537:9)
#36     GeneralizingAstVisitor.visitCompilationUnit (package:analyzer/dart/ast/visitor.dart:204:52)
#37     CompletenessTracker.visitCompilationUnit.<anonymous closure> (package:nnbd_migration/src/utilities/completeness_tracker.dart:52:24)
#38     PermissiveModeVisitor.reportExceptionsIfPermissive (package:nnbd_migration/src/utilities/permissive_mode.dart:26:24)
#39     CompletenessTracker.visitCompilationUnit (package:nnbd_migration/src/utilities/completeness_tracker.dart:43:5)
#40     CompilationUnitImpl.accept (package:analyzer/src/dart/ast/ast.dart:2310:50)
#41     NullabilityMigrationImpl.processInput (package:nnbd_migration/src/nullability_migration_impl.dart:223:12)
#42     NonNullableFix.processUnit (package:nnbd_migration/src/front_end/non_nullable_fix.dart:162:16)
#43     _FixCodeProcessor.runLaterPhases.<anonymous closure> (package:nnbd_migration/migration_cli.dart:1088:20)
#44     _FixCodeProcessor.processResources (package:nnbd_migration/migration_cli.dart:1020:26)
<asynchronous suspension>
#45     _FixCodeProcessor.runLaterPhases (package:nnbd_migration/migration_cli.dart:1086:5)
<asynchronous suspension>
#46     MigrationCliRunner.run (package:nnbd_migration/migration_cli.dart:695:24)
<asynchronous suspension>
#47     MigrateCommand.run (package:dartdev/src/commands/migrate.dart:37:7)
<asynchronous suspension>
#48     CommandRunner.runCommand (package:args/command_runner.dart:209:13)
<asynchronous suspension>
#49     DartdevRunner.runCommand (package:dartdev/dartdev.dart:231:18)
<asynchronous suspension>
#50     runDartdev (package:dartdev/dartdev.dart:66:16)
<asynchronous suspension>
#51     main (file:///opt/s/w/ir/x/w/sdk/pkg/dartdev/bin/dartdev.dart:11:3)
<asynchronous suspension>

[robbecker-wf]

Update: it seems that adding --ignore-errors bypasses this exception/crash and then the migration tool appears to work. I just hope it's not doing something differently or wrong because we're ignoring errors.

[stereotype441]

As of 1c7fe71, the null safety migration tool has been removed from active development and retired. No further work on the tool is planned.

If you still need help, or you believe this issue has been closed in error, please feel free to reopen.