FormatException: Missing extension byte (at offset 1)

[pishguy]

FormatException: Missing extension byte (at offset 1)
dart:io Stdin.readLineSync
package:build_runner_core/src/environment/io_environment.dart 84:27 IOEnvironment.prompt
package:build_runner_core/src/environment/overridable_environment.dart 63:16 OverrideableEnvironment.prompt
package:build_runner_core/src/environment/overridable_environment.dart 63:16 OverrideableEnvironment.prompt
package:build_runner_core/src/generate/build_definition.dart 546:41 _Loader._initialBuildCleanup
package:build_runner_core/src/generate/build_definition.dart 283:17 _Loader.prepareWorkspace.
package:build_runner_core/src/logging/logging.dart 25:30 logTimedAsync
package:build_runner_core/src/generate/build_definition.dart 280:13 _Loader.prepareWorkspace
package:build_runner_core/src/generate/build_impl.dart 114:27 BuildImpl.create
package:build_runner/src/generate/watch_impl.dart 347:26 WatchImpl._run.

[davidmorgan]

Please add more information about what you're doing--it's hard to guess from just the stack trace :)