NPE in GenericInferrer._matchInterfaceSubtypeOf.guardedInterfaceSubtype with new mixin syntax

[yjbanov]

Reproducible in flutter/flutter@a3e0b0a.

It seems to point at flutter analyze. However, it only breaks our dartdoc test and not the flutter analyze step.

analyzer stderr: #69     ResolverVisitor.visitArgumentList (package:analyzer/src/generated/resolver.dart:4367:18)
analyzer stderr: #70     ArgumentListImpl.accept (package:analyzer/src/dart/ast/ast.dart:419:49)
analyzer stderr: #71     ResolverVisitor.visitInstanceCreationExpression (package:analyzer/src/generated/resolver.dart:5127:24)
analyzer stderr: #72     InstanceCreationExpressionImpl.accept (package:analyzer/src/dart/ast/ast.dart:6513:15)
analyzer stderr: #73     ReturnStatementImpl.visitChildren (package:analyzer/src/dart/ast/ast.dart:9417:18)
analyzer stderr: #74     ResolverVisitor.visitNode (package:analyzer/src/generated/resolver.dart:5262:10)
analyzer stderr: #75     UnifyingAstVisitor.visitReturnStatement (package:analyzer/dart/ast/visitor.dart:3210:51)
analyzer stderr: #76     ResolverVisitor.visitReturnStatement (package:analyzer/src/generated/resolver.dart:5318:11)
analyzer stderr: #77     ReturnStatementImpl.accept (package:analyzer/src/dart/ast/ast.dart:9413:49)
analyzer stderr: #78     NodeListImpl.accept (package:analyzer/src/dart/ast/ast.dart:8324:20)
analyzer stderr: #79     ScopedVisitor.visitSwitchCase (package:analyzer/src/generated/resolver.dart:6691:23)
analyzer stderr: #80     ResolverVisitor.visitSwitchCase (package:analyzer/src/generated/resolver.dart:5355:13)
analyzer stderr: #81     SwitchCaseImpl.accept (package:analyzer/src/dart/ast/ast.dart:10274:49)
analyzer stderr: #82     NodeListImpl.accept (package:analyzer/src/dart/ast/ast.dart:8324:20)
analyzer stderr: #83     ResolverVisitor.visitSwitchStatementInScope (package:analyzer/src/generated/resolver.dart:5379:20)
analyzer stderr: #84     ScopedVisitor.visitSwitchStatement (package:analyzer/src/generated/resolver.dart:6724:7)
analyzer stderr: #85     SwitchStatementImpl.accept (package:analyzer/src/dart/ast/ast.dart:10464:49)
analyzer stderr: #86     NodeListImpl.accept (package:analyzer/src/dart/ast/ast.dart:8324:20)
analyzer stderr: #87     BlockImpl.visitChildren (package:analyzer/src/dart/ast/ast.dart:1240:17)
analyzer stderr: #88     ResolverVisitor.visitNode (package:analyzer/src/generated/resolver.dart:5262:10)
analyzer stderr: #89     UnifyingAstVisitor.visitBlock (package:analyzer/dart/ast/visitor.dart:2964:31)
analyzer stderr: #90     ScopedVisitor.visitBlock (package:analyzer/src/generated/resolver.dart:6149:13)
analyzer stderr: #91     BlockImpl.accept (package:analyzer/src/dart/ast/ast.dart:1236:49)
2018-10-23T13:51:14.534988: analyzer stderr: #92     BlockFunctionBodyImpl.visitChildren (package:analyzer/src/dart/ast/ast.dart:1185:13)
analyzer stderr: #93     ResolverVisitor.visitNode (package:analyzer/src/generated/resolver.dart:5262:10)
analyzer stderr: #94     UnifyingAstVisitor.visitBlockFunctionBody (package:analyzer/dart/ast/visitor.dart:2967:55)
analyzer stderr: #95     ScopedVisitor.visitBlockFunctionBody (package:analyzer/src/generated/resolver.dart:6161:13)
analyzer stderr: #96     ResolverVisitor.visitBlockFunctionBody (package:analyzer/src/generated/resolver.dart:4494:13)
2018-10-23T13:51:14.535049: analyzer stderr: #97     BlockFunctionBodyImpl.accept (package:analyzer/src/dart/ast/ast.dart:1181:49)
analyzer stderr: #98     FunctionExpressionImpl.visitChildren (package:analyzer/src/dart/ast/ast.dart:5366:12)
2018-10-23T13:51:14.535118: analyzer stderr: #99     ResolverVisitor.visitNode (package:analyzer/src/generated/resolver.dart:5262:10)
analyzer stderr: #100    UnifyingAstVisitor.visitFunctionExpression (package:analyzer/dart/ast/visitor.dart:3078:57)
2018-10-23T13:51:14.535188: analyzer stderr: #101    ScopedVisitor.visitFunctionExpression (package:analyzer/src/generated/resolver.dart:6482:15)
analyzer stderr: #102    ResolverVisitor.visitFunctionExpression (package:analyzer/src/generated/resolver.dart:4990:15)
2018-10-23T13:51:14.535245: analyzer stderr: #103    FunctionExpressionImpl.accept (package:analyzer/src/dart/ast/ast.dart:5360:49)
analyzer stderr: #104    NamedExpressionImpl.visitChildren (package:analyzer/src/dart/ast/ast.dart:8043:18)
2018-10-23T13:51:14.535297: analyzer stderr: #105    ResolverVisitor.visitNode (package:analyzer/src/generated/resolver.dart:5262:10)
2018-10-23T13:51:14.535353: analyzer stderr: #106    UnifyingAstVisitor.visitNamedExpression (package:analyzer/dart/ast/visitor.dart:3160:51)
analyzer stderr: #107    ResolverVisitor.visitNamedExpression (package:analyzer/src/generated/resolver.dart:5257:18)
2018-10-23T13:51:14.535406: analyzer stderr: #108    NamedExpressionImpl.accept (package:analyzer/src/dart/ast/ast.dart:8038:49)
2018-10-23T13:51:14.535461: analyzer stderr: #109    NodeListImpl.accept (package:analyzer/src/dart/ast/ast.dart:8324:20)
analyzer stderr: #110    ArgumentListImpl.visitChildren (package:analyzer/src/dart/ast/ast.dart:423:16)
2018-10-23T13:51:14.535512: analyzer stderr: #111    ResolverVisitor.visitNode (package:analyzer/src/generated/resolver.dart:5262:10)
2018-10-23T13:51:14.535565: analyzer stderr: #112    UnifyingAstVisitor.visitArgumentList (package:analyzer/dart/ast/visitor.dart:2943:45)
analyzer stderr: #113    ResolverVisitor.visitArgumentList (package:analyzer/src/generated/resolver.dart:4367:18)
2018-10-23T13:51:14.535628: analyzer stderr: #114    ArgumentListImpl.accept (package:analyzer/src/dart/ast/ast.dart:419:49)
analyzer stderr: #115    ResolverVisitor.visitInstanceCreationExpression (package:analyzer/src/generated/resolver.dart:5127:24)
2018-10-23T13:51:14.536180: analyzer stderr: #116    InstanceCreationExpressionImpl.accept (package:analyzer/src/dart/ast/ast.dart:6513:15)
analyzer stderr: #117    NodeListImpl.accept (package:analyzer/src/dart/ast/ast.dart:8324:20)
analyzer stderr: #118    ArgumentListImpl.visitChildren (package:analyzer/src/dart/ast/ast.dart:423:16)
analyzer stderr: #119    ResolverVisitor.visitNode (package:analyzer/src/generated/resolver.dart:5262:10)
analyzer stderr: #120    UnifyingAstVisitor.visitArgumentList (package:analyzer/dart/ast/visitor.dart:2943:45)
analyzer stderr: #121    ResolverVisitor.visitArgumentList (package:analyzer/src/generated/resolver.dart:4367:18)
analyzer stderr: #122    ArgumentListImpl.accept (package:analyzer/src/dart/ast/ast.dart:419:49)
analyzer stderr: #123    ResolverVisitor.visitMethodInvocation (package:analyzer/src/generated/resolver.dart:5224:24)
2018-10-23T13:51:14.537748: analyzer stderr: #124    MethodInvocationImpl.accept (package:analyzer/src/dart/ast/ast.dart:7827:49)
analyzer stderr: #125    AwaitExpressionImpl.visitChildren (package:analyzer/src/dart/ast/ast.dart:1013:18)
2018-10-23T13:51:14.537855: analyzer stderr: #126    ResolverVisitor.visitNode (package:analyzer/src/generated/resolver.dart:5262:10)
analyzer stderr: #127    UnifyingAstVisitor.visitAwaitExpression (package:analyzer/dart/ast/visitor.dart:2958:51)
analyzer stderr: #128    ResolverVisitor.visitAwaitExpression (package:analyzer/src/generated/resolver.dart:4407:18)
analyzer stderr: #129    AwaitExpressionImpl.accept (package:analyzer/src/dart/ast/ast.dart:1009:49)
2018-10-23T13:51:14.537936: analyzer stderr: #130    ExpressionStatementImpl.visitChildren (package:analyzer/src/dart/ast/ast.dart:4232:18)
analyzer stderr: #131    ResolverVisitor.visitNode (package:analyzer/src/generated/resolver.dart:5262:10)
analyzer stderr: #132    UnifyingAstVisitor.visitExpressionStatement (package:analyzer/dart/ast/visitor.dart:3050:59)
analyzer stderr: #133    ExpressionStatementImpl.accept (package:analyzer/src/dart/ast/ast.dart:4228:49)
2018-10-23T13:51:14.537997: analyzer stderr: #134    NodeListImpl.accept (package:analyzer/src/dart/ast/ast.dart:8324:20)
analyzer stderr: #135    BlockImpl.visitChildren (package:analyzer/src/dart/ast/ast.dart:1240:17)
2018-10-23T13:51:14.538054: analyzer stderr: #136    ResolverVisitor.visitNode (package:analyzer/src/generated/resolver.dart:5262:10)
analyzer stderr: #137    UnifyingAstVisitor.visitBlock (package:analyzer/dart/ast/visitor.dart:2964:31)
2018-10-23T13:51:14.538110: analyzer stderr: #138    ScopedVisitor.visitBlock (package:analyzer/src/generated/resolver.dart:6149:13)
analyzer stderr: #139    BlockImpl.accept (package:analyzer/src/dart/ast/ast.dart:1236:49)
2018-10-23T13:51:14.538168: analyzer stderr: #140    BlockFunctionBodyImpl.visitChildren (package:analyzer/src/dart/ast/ast.dart:1185:13)
analyzer stderr: #141    ResolverVisitor.visitNode (package:analyzer/src/generated/resolver.dart:5262:10)
2018-10-23T13:51:14.538234: analyzer stderr: #142    UnifyingAstVisitor.visitBlockFunctionBody (package:analyzer/dart/ast/visitor.dart:2967:55)
analyzer stderr: #143    ScopedVisitor.visitBlockFunctionBody (package:analyzer/src/generated/resolver.dart:6161:13)
2018-10-23T13:51:14.538291: analyzer stderr: #144    ResolverVisitor.visitBlockFunctionBody (package:analyzer/src/generated/resolver.dart:4494:13)
analyzer stderr: #145    BlockFunctionBodyImpl.accept (package:analyzer/src/dart/ast/ast.dart:1181:49)
2018-10-23T13:51:14.538347: analyzer stderr: #146    FunctionExpressionImpl.visitChildren (package:analyzer/src/dart/ast/ast.dart:5366:12)
analyzer stderr: #147    ResolverVisitor.visitNode (package:analyzer/src/generated/resolver.dart:5262:10)
2018-10-23T13:51:14.538403: analyzer stderr: #148    UnifyingAstVisitor.visitFunctionExpression (package:analyzer/dart/ast/visitor.dart:3078:57)
analyzer stderr: #149    ScopedVisitor.visitFunctionExpression (package:analyzer/src/generated/resolver.dart:6482:15)
2018-10-23T13:51:14.538462: analyzer stderr: #150    ResolverVisitor.visitFunctionExpression (package:analyzer/src/generated/resolver.dart:4990:15)
analyzer stderr: #151    FunctionExpressionImpl.accept (package:analyzer/src/dart/ast/ast.dart:5360:49)
2018-10-23T13:51:14.538518: analyzer stderr: #152    NodeListImpl.accept (package:analyzer/src/dart/ast/ast.dart:8324:20)
analyzer stderr: #153    ArgumentListImpl.visitChildren (package:analyzer/src/dart/ast/ast.dart:423:16)
2018-10-23T13:51:14.538571: analyzer stderr: #154    ResolverVisitor.visitNode (package:analyzer/src/generated/resolver.dart:5262:10)
analyzer stderr: #155    UnifyingAstVisitor.visitArgumentList (package:analyzer/dart/ast/visitor.dart:2943:45)
2018-10-23T13:51:14.538858: analyzer stderr: #156    ResolverVisitor.visitArgumentList (package:analyzer/src/generated/resolver.dart:4367:18)
analyzer stderr: #157    ArgumentListImpl.accept (package:analyzer/src/dart/ast/ast.dart:419:49)
analyzer stderr: #158    ResolverVisitor.visitMethodInvocation (package:analyzer/src/generated/resolver.dart:5224:24)
analyzer stderr: #159    MethodInvocationImpl.accept (package:analyzer/src/dart/ast/ast.dart:7827:49)
analyzer stderr: #160    ExpressionStatementImpl.visitChildren (package:analyzer/src/dart/ast/ast.dart:4232:18)
analyzer stderr: #161    ResolverVisitor.visitNode (package:analyzer/src/generated/resolver.dart:5262:10)
analyzer stderr: #162    UnifyingAstVisitor.visitExpressionStatement (package:analyzer/dart/ast/visitor.dart:3050:59)
analyzer stderr: #163    ExpressionStatementImpl.accept (package:analyzer/src/dart/ast/ast.dart:4228:49)
analyzer stderr: #164    NodeListImpl.accept (package:analyzer/src/dart/ast/ast.dart:8324:20)
analyzer stderr: #165    BlockImpl.visitChildren (package:analyzer/src/dart/ast/ast.dart:1240:17)
analyzer stderr: #166    ResolverVisitor.visitNode (package:analyzer/src/generated/resolver.dart:5262:10)
2018-10-23T13:51:14.538954: analyzer stderr: #167    UnifyingAstVisitor.visitBlock (package:analyzer/dart/ast/visitor.dart:2964:31)
analyzer stderr: #168    ScopedVisitor.visitBlock (package:analyzer/src/generated/resolver.dart:6149:13)
analyzer stderr: #169    BlockImpl.accept (package:analyzer/src/dart/ast/ast.dart:1236:49)
analyzer stderr: #170    BlockFunctionBodyImpl.visitChildren (package:analyzer/src/dart/ast/ast.dart:1185:13)
2018-10-23T13:51:14.539019: analyzer stderr: #171    ResolverVisitor.visitNode (package:analyzer/src/generated/resolver.dart:5262:10)
analyzer stderr: #172    UnifyingAstVisitor.visitBlockFunctionBody (package:analyzer/dart/ast/visitor.dart:2967:55)
analyzer stderr: #173    ScopedVisitor.visitBlockFunctionBody (package:analyzer/src/generated/resolver.dart:6161:13)
2018-10-23T13:51:14.539077: analyzer stderr: #174    ResolverVisitor.visitBlockFunctionBody (package:analyzer/src/generated/resolver.dart:4494:13)
analyzer stderr: #175    BlockFunctionBodyImpl.accept (package:analyzer/src/dart/ast/ast.dart:1181:49)
2018-10-23T13:51:14.539135: analyzer stderr: #176    FunctionExpressionImpl.visitChildren (package:analyzer/src/dart/ast/ast.dart:5366:12)
analyzer stderr: #177    ResolverVisitor.visitNode (package:analyzer/src/generated/resolver.dart:5262:10)
2018-10-23T13:51:14.539191: analyzer stderr: #178    UnifyingAstVisitor.visitFunctionExpression (package:analyzer/dart/ast/visitor.dart:3078:57)
analyzer stderr: #179    ScopedVisitor.visitFunctionExpression (package:analyzer/src/generated/resolver.dart:6457:13)
2018-10-23T13:51:14.539249: analyzer stderr: #180    ResolverVisitor.visitFunctionExpression (package:analyzer/src/generated/resolver.dart:4990:15)
analyzer stderr: #181    FunctionExpressionImpl.accept (package:analyzer/src/dart/ast/ast.dart:5360:49)
2018-10-23T13:51:14.539305: analyzer stderr: #182    FunctionDeclarationImpl.visitChildren (package:analyzer/src/dart/ast/ast.dart:5204:26)
analyzer stderr: #183    ResolverVisitor.visitNode (package:analyzer/src/generated/resolver.dart:5262:10)
2018-10-23T13:51:14.539360: analyzer stderr: #184    UnifyingAstVisitor.visitFunctionDeclaration (package:analyzer/dart/ast/visitor.dart:3071:59)
analyzer stderr: #185    ScopedVisitor.visitFunctionDeclarationInScope (package:analyzer/src/generated/resolver.dart:6450:11)
2018-10-23T13:51:14.539425: analyzer stderr: #186    ResolverVisitor.visitFunctionDeclarationInScope (package:analyzer/src/generated/resolver.dart:4966:11)
analyzer stderr: #187    ScopedVisitor.visitFunctionDeclaration (package:analyzer/src/generated/resolver.dart:6442:7)
analyzer stderr: #188    ResolverVisitor.visitFunctionDeclaration (package:analyzer/src/generated/resolver.dart:4956:13)
2018-10-23T13:51:14.539586: analyzer stderr: #189    FunctionDeclarationImpl.accept (package:analyzer/src/dart/ast/ast.dart:5197:49)
analyzer stderr: #190    ResolverVisitor.visitCompilationUnit (package:analyzer/src/generated/resolver.dart:4597:25)
analyzer stderr: #191    CompilationUnitImpl.accept (package:analyzer/src/dart/ast/ast.dart:2416:49)
analyzer stderr: #192    LibraryAnalyzer._resolveFile (package:analyzer/src/dart/analysis/library_analyzer.dart:604:10)
analyzer stderr: #193    LibraryAnalyzer._analyze. (package:analyzer/src/dart/analysis/library_analyzer.dart:109:9)
2018-10-23T13:51:14.539666: analyzer stderr: #194    __InternalLinkedHashMap&_HashVMBase&MapMixin&_LinkedHashMapMixin.forEach (dart:collection/runtime/libcompact_hash.dart:370:8)
analyzer stderr: #195    LibraryAnalyzer._analyze (package:analyzer/src/dart/analysis/library_analyzer.dart:108:13)
2018-10-23T13:51:14.539729: analyzer stderr: #196    LibraryAnalyzer.analyze. (package:analyzer/src/dart/analysis/library_analyzer.dart:84:14)
analyzer stderr: 
2018-10-23T13:51:14.539785: analyzer stderr: #197    _PerformanceTagImpl.makeCurrentWhileAsync (package:analyzer/src/generated/utilities_general.dart:270:21)
analyzer stderr: 
2018-10-23T13:51:14.539857: analyzer stderr: #198    LibraryAnalyzer.analyze (package:analyzer/src/dart/analysis/library_analyzer.dart:83:43)
analyzer stderr: 
2018-10-23T13:51:14.539914: analyzer stderr: #199    AnalysisDriver._computeAnalysisResult. (package:analyzer/src/dart/analysis/driver.dart:1248:71)
analyzer stderr: 
analyzer stderr: #200    PerformanceLog.runAsync (package:analyzer/src/dart/analysis/performance_logger.dart:52:21)
2018-10-23T13:51:14.539969: analyzer stderr: 
analyzer stderr: #201    AnalysisDriver._computeAnalysisResult (package:analyzer/src/dart/analysis/driver.dart:1224:20)
2018-10-23T13:51:14.540034: analyzer stderr: 
analyzer stderr: #202    AnalysisDriver.performWork (package:analyzer/src/dart/analysis/driver.dart:1050:39)
2018-10-23T13:51:14.540089: analyzer stderr: 
analyzer stderr: #203    AnalysisDriverScheduler._run (package:analyzer/src/dart/analysis/driver.dart:1891:24)
2018-10-23T13:51:14.540143: analyzer stderr: 
analyzer stderr: #204    AnalysisDriverScheduler.start (package:analyzer/src/dart/analysis/driver.dart:1832:5)
2018-10-23T13:51:14.540199: analyzer stderr: #205    new AnalysisServer (package:analysis_server/src/analysis_server.dart:340:29)
analyzer stderr: #206    SocketServer.createAnalysisServer (package:analysis_server/src/socket_server.dart:79:26)
2018-10-23T13:51:14.540255: analyzer stderr: #207    StdioAnalysisServer.serveStdio (package:analysis_server/src/server/stdio_server.dart:37:18)
analyzer stderr: #208    Driver.start. (package:analysis_server/src/server/driver.dart:505:21)
2018-10-23T13:51:14.540311: analyzer stderr: #209    _rootRun (dart:async/zone.dart:1124:13)
analyzer stderr: #210    _CustomZone.run (dart:async/zone.dart:1021:19)
2018-10-23T13:51:14.540363: analyzer stderr: #211    _runZoned (dart:async/zone.dart:1516:10)
analyzer stderr: #212    runZoned (dart:async/zone.dart:1463:12)
2018-10-23T13:51:14.540418: analyzer stderr: #213    Driver._captureExceptions (package:analysis_server/src/server/driver.dart:551:12)
analyzer stderr: #214    Driver.start (package:analysis_server/src/server/driver.dart:503:7)
2018-10-23T13:51:14.540480: analyzer stderr: #215    main (file:///b/build/slave/Linux_Engine/build/src/third_party/dart/pkg/analysis_server/bin/server.dart:12:11)
analyzer stderr: #216    _AsyncAwaitCompleter.start (dart:async/runtime/libasync_patch.dart:49:6)
2018-10-23T13:51:14.540538: analyzer stderr: #217    main (file:///b/build/slave/Linux_Engine/build/src/third_party/dart/pkg/analysis_server/bin/server.dart:10:10)
analyzer stderr: #218    _startIsolate. (dart:isolate/runtime/libisolate_patch.dart:287:32)
analyzer stderr: #219    _RawReceivePortImpl._handleMessage (dart:isolate/runtime/libisolate_patch.dart:171:12)
2018-10-23T13:51:14.540602: analyzer stderr: 
analyzer stderr: 
2018-10-23T13:51:14.549685: Task failed: Exception: flutter analyze had unexpected output (we saw 234 unexpected lines)2018-10-23T13:51:14.549804: 

Full log

/cc @JekCharlsonYu @jcollins-g

[bwilkerson]

Do you have the top of the stack? (I can't access the "Full log" link.)

[yjbanov]

Here's another stack-trace:

2018-10-23T13:51:14.530630: analyzer stderr: Error from the analysis server: Analysis failed: /home/linux1/.cocoon/flutter/packages/flutter/test/widgets/page_forward_transitions_test.dart context: exception_20181023_135047_417
2018-10-23T13:51:14.530904: analyzer stderr: NoSuchMethodError: The getter 'element' was called on null.
2018-10-23T13:51:14.530982: analyzer stderr: Receiver: null
analyzer stderr: Tried calling: element
analyzer stderr: #0      Object.noSuchMethod (dart:core/runtime/libobject_patch.dart:50:5)
2018-10-23T13:51:14.531050: analyzer stderr: #1      GenericInferrer._matchInterfaceSubtypeOf.guardedInterfaceSubtype (package:analyzer/src/generated/type_system.dart:493:29)
2018-10-23T13:51:14.531110: analyzer stderr: #2      GenericInferrer._matchInterfaceSubtypeOf (package:analyzer/src/generated/type_system.dart:511:32)
analyzer stderr: #3      GenericInferrer._matchInterfaceSubtypeOf.guardedInterfaceSubtype (package:analyzer/src/generated/type_system.dart:494:24)
2018-10-23T13:51:14.531167: analyzer stderr: #4      GenericInferrer._matchInterfaceSubtypeOf (package:analyzer/src/generated/type_system.dart:516:34)
2018-10-23T13:51:14.531223: analyzer stderr: #5      GenericInferrer._matchSubtypeOf (package:analyzer/src/generated/type_system.dart:656:14)
2018-10-23T13:51:14.531276: analyzer stderr: #6      GenericInferrer.tryMatchSubtypeOf (package:analyzer/src/generated/type_system.dart:271:20)
2018-10-23T13:51:14.531334: analyzer stderr: #7      GenericInferrer.constrainReturnType (package:analyzer/src/generated/type_system.dart:136:5)
analyzer stderr: #8      StrongTypeSystemImpl.inferGenericFunctionOrType (package:analyzer/src/generated/type_system.dart:904:16)
2018-10-23T13:51:14.531389: analyzer stderr: #9      ResolverVisitor._inferArgumentTypesForGeneric (package:analyzer/src/generated/resolver.dart:5659:17)
2018-10-23T13:51:14.531443: analyzer stderr: #10     ResolverVisitor._inferArgumentTypesForInvocation (package:analyzer/src/generated/resolver.dart:5734:25)
2018-10-23T13:51:14.531501: analyzer stderr: #11     ResolverVisitor.visitMethodInvocation (package:analyzer/src/generated/resolver.dart:5223:5)
2018-10-23T13:51:14.531570: analyzer stderr: #12     MethodInvocationImpl.accept (package:analyzer/src/dart/ast/ast.dart:7827:49)
analyzer stderr: #13     VariableDeclarationImpl.visitChildren (package:analyzer/src/dart/ast/ast.dart:11407:19)
2018-10-23T13:51:14.531626: analyzer stderr: #14     ResolverVisitor.visitNode (package:analyzer/src/generated/resolver.dart:5262:10)
2018-10-23T13:51:14.531679: analyzer stderr: #15     UnifyingAstVisitor.visitVariableDeclaration (package:analyzer/dart/ast/visitor.dart:3275:59)
analyzer stderr: #16     ScopedVisitor.visitVariableDeclaration (package:analyzer/src/generated/resolver.dart:6738:11)
2018-10-23T13:51:14.531732: analyzer stderr: #17     ResolverVisitor.visitVariableDeclaration (package:analyzer/src/generated/resolver.dart:5406:11)
2018-10-23T13:51:14.531785: analyzer stderr: #18     VariableDeclarationImpl.accept (package:analyzer/src/dart/ast/ast.dart:11401:49)
2018-10-23T13:51:14.531837: analyzer stderr: #19     NodeListImpl.accept (package:analyzer/src/dart/ast/ast.dart:8324:20)
2018-10-23T13:51:14.531889: analyzer stderr: #20     VariableDeclarationListImpl.visitChildren (package:analyzer/src/dart/ast/ast.dart:11503:16)
2018-10-23T13:51:14.531951: analyzer stderr: #21     ResolverVisitor.visitNode (package:analyzer/src/generated/resolver.dart:5262:10)
analyzer stderr: #22     UnifyingAstVisitor.visitVariableDeclarationList (package:analyzer/dart/ast/visitor.dart:3279:7)
2018-10-23T13:51:14.532006: analyzer stderr: #23     ResolverVisitor.visitVariableDeclarationList (package:analyzer/src/generated/resolver.dart:5430:11)
2018-10-23T13:51:14.532057: analyzer stderr: #24     VariableDeclarationListImpl.accept (package:analyzer/src/dart/ast/ast.dart:11497:15)
2018-10-23T13:51:14.532112: analyzer stderr: #25     VariableDeclarationStatementImpl.visitChildren (package:analyzer/src/dart/ast/ast.dart:11558:20)
2018-10-23T13:51:14.532170: analyzer stderr: #26     ResolverVisitor.visitNode (package:analyzer/src/generated/resolver.dart:5262:10)
2018-10-23T13:51:14.532225: analyzer stderr: #27     UnifyingAstVisitor.visitVariableDeclarationStatement (package:analyzer/dart/ast/visitor.dart:3283:7)
2018-10-23T13:51:14.532285: analyzer stderr: #28     VariableDeclarationStatementImpl.accept (package:analyzer/src/dart/ast/ast.dart:11554:15)
2018-10-23T13:51:14.532339: analyzer stderr: #29     NodeListImpl.accept (package:analyzer/src/dart/ast/ast.dart:8324:20)
2018-10-23T13:51:14.532391: analyzer stderr: #30     BlockImpl.visitChildren (package:analyzer/src/dart/ast/ast.dart:1240:17)
2018-10-23T13:51:14.532441: analyzer stderr: #31     ResolverVisitor.visitNode (package:analyzer/src/generated/resolver.dart:5262:10)
2018-10-23T13:51:14.532494: analyzer stderr: #32     UnifyingAstVisitor.visitBlock (package:analyzer/dart/ast/visitor.dart:2964:31)
2018-10-23T13:51:14.532546: analyzer stderr: #33     ScopedVisitor.visitBlock (package:analyzer/src/generated/resolver.dart:6149:13)
2018-10-23T13:51:14.532598: analyzer stderr: #34     BlockImpl.accept (package:analyzer/src/dart/ast/ast.dart:1236:49)
2018-10-23T13:51:14.532653: analyzer stderr: #35     BlockFunctionBodyImpl.visitChildren (package:analyzer/src/dart/ast/ast.dart:1185:13)
2018-10-23T13:51:14.532715: analyzer stderr: #36     ResolverVisitor.visitNode (package:analyzer/src/generated/resolver.dart:5262:10)
2018-10-23T13:51:14.532779: analyzer stderr: #37     UnifyingAstVisitor.visitBlockFunctionBody (package:analyzer/dart/ast/visitor.dart:2967:55)
2018-10-23T13:51:14.532834: analyzer stderr: #38     ScopedVisitor.visitBlockFunctionBody (package:analyzer/src/generated/resolver.dart:6161:13)
2018-10-23T13:51:14.532888: analyzer stderr: #39     ResolverVisitor.visitBlockFunctionBody (package:analyzer/src/generated/resolver.dart:4494:13)
2018-10-23T13:51:14.532939: analyzer stderr: #40     BlockFunctionBodyImpl.accept (package:analyzer/src/dart/ast/ast.dart:1181:49)
2018-10-23T13:51:14.532984: analyzer stderr: #41     FunctionExpressionImpl.visitChildren (package:analyzer/src/dart/ast/ast.dart:5366:12)
2018-10-23T13:51:14.533140: analyzer stderr: #42     ResolverVisitor.visitNode (package:analyzer/src/generated/resolver.dart:5262:10)
2018-10-23T13:51:14.533207: analyzer stderr: #43     UnifyingAstVisitor.visitFunctionExpression (package:analyzer/dart/ast/visitor.dart:3078:57)
analyzer stderr: #44     ScopedVisitor.visitFunctionExpression (package:analyzer/src/generated/resolver.dart:6482:15)
2018-10-23T13:51:14.533262: analyzer stderr: #45     ResolverVisitor.visitFunctionExpression (package:analyzer/src/generated/resolver.dart:4990:15)
analyzer stderr: #46     FunctionExpressionImpl.accept (package:analyzer/src/dart/ast/ast.dart:5360:49)
2018-10-23T13:51:14.533316: analyzer stderr: #47     NamedExpressionImpl.visitChildren (package:analyzer/src/dart/ast/ast.dart:8043:18)
2018-10-23T13:51:14.533370: analyzer stderr: #48     ResolverVisitor.visitNode (package:analyzer/src/generated/resolver.dart:5262:10)
analyzer stderr: #49     UnifyingAstVisitor.visitNamedExpression (package:analyzer/dart/ast/visitor.dart:3160:51)
2018-10-23T13:51:14.533431: analyzer stderr: #50     ResolverVisitor.visitNamedExpression (package:analyzer/src/generated/resolver.dart:5257:18)
2018-10-23T13:51:14.533487: analyzer stderr: #51     NamedExpressionImpl.accept (package:analyzer/src/dart/ast/ast.dart:8038:49)
analyzer stderr: #52     NodeListImpl.accept (package:analyzer/src/dart/ast/ast.dart:8324:20)
2018-10-23T13:51:14.533545: analyzer stderr: #53     ArgumentListImpl.visitChildren (package:analyzer/src/dart/ast/ast.dart:423:16)
analyzer stderr: #54     ResolverVisitor.visitNode (package:analyzer/src/generated/resolver.dart:5262:10)
2018-10-23T13:51:14.533597: analyzer stderr: #55     UnifyingAstVisitor.visitArgumentList (package:analyzer/dart/ast/visitor.dart:2943:45)
2018-10-23T13:51:14.533651: analyzer stderr: #56     ResolverVisitor.visitArgumentList (package:analyzer/src/generated/resolver.dart:4367:18)
analyzer stderr: #57     ArgumentListImpl.accept (package:analyzer/src/dart/ast/ast.dart:419:49)
2018-10-23T13:51:14.533705: analyzer stderr: #58     ResolverVisitor.visitInstanceCreationExpression (package:analyzer/src/generated/resolver.dart:5127:24)
2018-10-23T13:51:14.533758: analyzer stderr: #59     InstanceCreationExpressionImpl.accept (package:analyzer/src/dart/ast/ast.dart:6513:15)
analyzer stderr: #60     NamedExpressionImpl.visitChildren (package:analyzer/src/dart/ast/ast.dart:8043:18)
2018-10-23T13:51:14.533811: analyzer stderr: #61     ResolverVisitor.visitNode (package:analyzer/src/generated/resolver.dart:5262:10)
2018-10-23T13:51:14.533868: analyzer stderr: #62     UnifyingAstVisitor.visitNamedExpression (package:analyzer/dart/ast/visitor.dart:3160:51)
2018-10-23T13:51:14.533936: analyzer stderr: #63     ResolverVisitor.visitNamedExpression (package:analyzer/src/generated/resolver.dart:5257:18)
analyzer stderr: #64     NamedExpressionImpl.accept (package:analyzer/src/dart/ast/ast.dart:8038:49)
analyzer stderr: #65     NodeListImpl.accept (package:analyzer/src/dart/ast/ast.dart:8324:20)
2018-10-23T13:51:14.533991: analyzer stderr: #66     ArgumentListImpl.visitChildren (package:analyzer/src/dart/ast/ast.dart:423:16)
2018-10-23T13:51:14.534043: analyzer stderr: #67     ResolverVisitor.visitNode (package:analyzer/src/generated/resolver.dart:5262:10)
analyzer stderr: #68     UnifyingAstVisitor.visitArgumentList (package:analyzer/dart/ast/visitor.dart:2943:45)

[bwilkerson]

@stereotype441 I believe that you're most familiar with GenericInferrer. Could you take a look?

[stereotype441]

@bwilkerson Sure, having a look now. @yjbanov, can you provide repro instructions? I'm not sure which dartdoc test you're referring to or how to run it. In the meantime I'll start following my nose based on the stacktrace.

[stereotype441]

Successfully reproduced an exception with a similar stacktrace by running dartanalyzer on the following test program:

class C<T> {}

mixin M<T> on C<T> {}

M<T> f<T>() => null;

main() {
  C<int> c = f();
}

I see the problem: GenericInferrer._matchInterfaceSubtypeOf was never updated to account for the fact that classes other than Object may now lack a superclass.

Doing some experiments now to figure out what the behavior should be so that I can make a proper fix.

[stereotype441]

Fix out for review: https://dart-review.googlesource.com/c/sdk/+/81322

[jcollins-g]

Looking into this with dartdoc itself -- the exceptions are from the --dartdocs mode of flutter analyze but I'd be surprised the bug is isolated to analyzer unless the bug was introduced after 0.33.0.

[Hixie]

I see this with regular analyzer too, intermittently.

[stereotype441]

@Hixie that's not surprising--the bug was in the analyzer itself, not dartdoc. It should be fixed as of SDK commit 0009ca7. Let us know if you continue to see it in any version of the SDK after that.