dart migrate bug

[MuteMuty]

When I wanted to migrate to null-safety an error occurred and it said to fill the report here, so this is what I am doing. I than proceeded to use the command dart migrate --ignore-exceptions to bypass this error.

x@1014-ubuntu-x:~/flutter/x$ dart migrate
`Migrating /home/x/flutter/x
See https://dart.dev/go/null-safety-migration for a migration guide.

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

Generating migration suggestions...
[------------------------------------------------------------------------------------------------------ ]Aborting migration due to an exception. This most likely is due to a
bug in the migration tool. Please consider filing a bug report at:

https://github.com/dart-lang/sdk/issues/new
Please include the SDK version (2.18.4) in your bug report.

To attempt to perform migration anyway, you may re-run with
--ignore-exceptions.

Exception details:

Null check operator used on a null value at offset 1492 in /home/x/flutter/x/lib/src/blocs/language_bloc/language_bloc.dart (SharedPreferencesService?.instance)

#0 EdgeBuilder._handlePropertyAccessGeneralized (package:nnbd_migration/src/edge_builder.dart:3186:46)
#1 EdgeBuilder._handlePropertyAccess (package:nnbd_migration/src/edge_builder.dart:3124:12)
#2 EdgeBuilder.visitPropertyAccess (package:nnbd_migration/src/edge_builder.dart:1649:12)
#3 PropertyAccessImpl.accept (package:analyzer/src/dart/ast/ast.dart:9230:50)
#4 EdgeBuilder._dispatch (package:nnbd_migration/src/edge_builder.dart:2341:24)
#5 EdgeBuilder.visitAwaitExpression (package:nnbd_migration/src/edge_builder.dart:503:26)
#6 AwaitExpressionImpl.accept (package:analyzer/src/dart/ast/ast.dart:981:50)
#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.visitVariableDeclarationList (package:nnbd_migration/src/edge_builder.dart:2040:11)
#10 VariableDeclarationListImpl.accept (package:analyzer/src/dart/ast/ast.dart:11673:15)
#11 EdgeBuilder._dispatch (package:nnbd_migration/src/edge_builder.dart:2341:24)
#12 EdgeBuilder.visitNode (package:nnbd_migration/src/edge_builder.dart:1537:9)
#13 GeneralizingAstVisitor.visitStatement (package:analyzer/dart/ast/visitor.dart:560:40)
#14 GeneralizingAstVisitor.visitVariableDeclarationStatement (package:analyzer/dart/ast/visitor.dart:636:7)
#15 VariableDeclarationStatementImpl.accept (package:analyzer/src/dart/ast/ast.dart:11722:15)
#16 EdgeBuilder._dispatch (package:nnbd_migration/src/edge_builder.dart:2341:24)
#17 EdgeBuilder.visitNode (package:nnbd_migration/src/edge_builder.dart:1537:9)
#18 GeneralizingAstVisitor.visitStatement (package:analyzer/dart/ast/visitor.dart:560:40)
#19 GeneralizingAstVisitor.visitBlock (package:analyzer/dart/ast/visitor.dart:167:32)
#20 BlockImpl.accept (package:analyzer/src/dart/ast/ast.dart:1183:50)
#21 EdgeBuilder._dispatch (package:nnbd_migration/src/edge_builder.dart:2341:24)
#22 EdgeBuilder.visitNode (package:nnbd_migration/src/edge_builder.dart:1537:9)
#23 GeneralizingAstVisitor.visitFunctionBody (package:analyzer/dart/ast/visitor.dart:338:46)
#24 GeneralizingAstVisitor.visitBlockFunctionBody (package:analyzer/dart/ast/visitor.dart:170:56)
#25 BlockFunctionBodyImpl.accept (package:analyzer/src/dart/ast/ast.dart:1134:50)
#26 EdgeBuilder._dispatch (package:nnbd_migration/src/edge_builder.dart:2341:24)
#27 EdgeBuilder.visitFunctionExpression. (package:nnbd_migration/src/edge_builder.dart:1035:25)
#28 ScopedSet.doScoped (package:nnbd_migration/src/utilities/scoped_set.dart:48:13)
#29 EdgeBuilder.visitFunctionExpression (package:nnbd_migration/src/edge_builder.dart:1033:28)
#30 FunctionExpressionImpl.accept (package:analyzer/src/dart/ast/ast.dart:5440:50)
#31 EdgeBuilder._dispatch (package:nnbd_migration/src/edge_builder.dart:2341:24)
#32 EdgeBuilder.visitFunctionDeclaration (package:nnbd_migration/src/edge_builder.dart:982:9)
#33 FunctionDeclarationImpl.accept (package:analyzer/src/dart/ast/ast.dart:5312:50)
#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. (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. (package:nnbd_migration/migration_cli.dart:1088:20)
#44 _FixCodeProcessor.processResources (package:nnbd_migration/migration_cli.dart:1020:26)

#45 _FixCodeProcessor.runLaterPhases (package:nnbd_migration/migration_cli.dart:1086:5)

#46 MigrationCliRunner.run (package:nnbd_migration/migration_cli.dart:695:24)

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

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

#49 DartdevRunner.runCommand (package:dartdev/dartdev.dart:231:18)

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

#51 main (file:///b/s/w/ir/x/w/sdk/pkg/dartdev/bin/dartdev.dart:11:3)
`

[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.