迁移到Dart 2时，出现“检查导入错误”，这意味着尚未生成某些模板

Question

I'm trying to migrate to Dart 2, I have a lot of packages and up to now I could do my job with not so much problems. Now I'm getting a strange error bot with DDC and dart2js:

[SEVERE] build_web_compilers|entrypoint on web/main.dart (cached):
Unable to find modules for some sources, this is usually the result of either a
bad import, a missing dependency in a package (or possibly a dev_dependency
needs to move to a real dependency), or a build failure (if importing a
generated file).

Please check the following imports:

`import 'package:ledger_web/src/ui/components/main_selection_bar.template.dart';` from ledger_web|lib/src/ui/components/service/main_selection_bar_service.dart at 7:1
`import 'package:ledger_web/src/ui/components/main_selection_bar.template.dart';` from ledger_web|lib/src/ui/components/service/main_selection_bar_service.template.dart at 11:1

... and more

It is correct to signal that there is not the import (MainSelectionBar is an angular component), because the template has not been generated. Now the problem is, why the template is not there? I checked the .dart_tool/build/generated directory but the template has not been created. I have a similar package with a similar component that works fine, so I cannot figure out what's happened. Is there a place where there is a more detailed error list? Interestingly enough, there is also a case in which the template exists, but it is listed like if it was not found.... Any hint?

Answer 1

Most likely this is related to a build failure when generating the template, which is not being properly reported on subsequent builds. This pull request should help that https://github.com/dart-lang/build/pull/1834/ , but you can also try running pub run build_runner clean and then doing a new build to get the original error back.