Build: NoSuchMethodError: The getter 'futureDynamicType' was called on null.

[MHamza600]

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[natebosch]

Can you please add some of the other details we requested in the issue template?

What version of build_runner and analyzer are you using? Where and how does this error surface? Does it give you a longer stack trace you can paste here?

[skreborn]

@natebosch I'm also getting the same error. It might be worth mentioning that I'm using Dart through Flutter.

I'm running Dart 2.6.0-dev.5.0 on Windows 10 (1903) with the packages [email protected], and [email protected].

I'm using the builder provided by json_serializable.

The command flutter pub run build_runner build results in the following:

[INFO] Generating build script...
[INFO] Generating build script completed, took 382ms

[WARNING] Deleted previous snapshot due to missing asset graph.
[INFO] Creating build script snapshot......
[INFO] Creating build script snapshot... completed, took 2m 18s

[INFO] Initializing inputs
[INFO] Building new asset graph...
[INFO] Building new asset graph completed, took 5.0s

[INFO] Checking for unexpected pre-existing outputs....
[INFO] Checking for unexpected pre-existing outputs. completed, took 1ms

[INFO] Running build...


You have hit a bug in build_runner
Please file an issue with reproduction steps at https://github.com/dart-lang/build/issues


NoSuchMethodError: The getter 'futureDynamicType' was called on null.
Receiver: null
Tried calling: futureDynamicType
dart:core                                                       Object.noSuchMethod
package:analyzer/src/dart/element/element.dart 6640:40          LibraryElementImpl.createLoadLibraryFunctionForLibrary
package:analyzer/src/dart/element/element.dart 6490:9           LibraryElementImpl.createLoadLibraryFunction
package:analyzer/src/summary/resynthesize.dart 339:24           SummaryResynthesizer.getLibraryElement.<fn>
dart:collection                                                 _LinkedHashMapMixin.putIfAbsent
package:analyzer/src/summary/resynthesize.dart 327:36           SummaryResynthesizer.getLibraryElement
package:analyzer/src/summary/resynthesize.dart 390:20           SummaryResynthesizer._buildTypeProvider
package:analyzer/src/summary/resynthesize.dart 178:5            new SummaryResynthesizer
package:analyzer/src/summary/package_bundle_reader.dart 351:9   new StoreBasedSummaryResynthesizer
package:analyzer/src/summary/package_bundle_reader.dart 327:26  ResynthesizerResultProvider.createResynthesizer
package:analyzer/src/summary/package_bundle_reader.dart 85:5    new InputPackagesResultProvider
package:analyzer/src/dart/analysis/library_context.dart 75:24   new LibraryContext
package:analyzer/src/dart/analysis/driver.dart 1612:29          AnalysisDriver._createLibraryContext
package:analyzer/src/dart/analysis/driver.dart 1556:26          AnalysisDriver._computeUnitElement
package:analyzer/src/dart/analysis/driver.dart 1158:34          AnalysisDriver.performWork
package:analyzer/src/dart/analysis/driver.dart 2145:24          AnalysisDriverScheduler._run
package:analyzer/src/dart/analysis/driver.dart 2075:5           AnalysisDriverScheduler.start
package:build_resolvers/src/analysis_driver.dart 55:13          analysisDriver
package:build_resolvers/src/resolver.dart 138:18                new AnalyzerResolvers
package:build_runner_core/src/generate/options.dart 192:19      BuildOptions.create
package:build_runner/src/generate/build.dart 85:36              build
package:build_runner/src/entrypoint/build.dart 28:24            BuildCommand.run
package:args/command_runner.dart 197:27                         CommandRunner.runCommand
package:args/command_runner.dart 112:25                         CommandRunner.run.<fn>
dart:async                                                      new Future.sync
package:args/command_runner.dart 112:14                         CommandRunner.run
package:build_runner/src/entrypoint/run.dart 24:31              run
.dart_tool\build\entrypoint\build.dart 22:22                    main

pub finished with exit code 1

[skreborn]

Running pub upgrade installed [email protected] and solved the issue for me.

[jakemac53]

Closing as it appears a pub upgrade will fix things