Compiler throws "AnalysisException: Cannot compute LIBRARY_ELEMENT" a few times a day

[dotdotcommadot]

The problem I have a large AngularDart project, consisting out of multiple external libraries. I started development on this project about 1.5 years ago in Dart 1, but since upgrading to Dart 2, the compiler seems to crash a few times a day, sometimes a few times an hour. It will throw a large error (see underneath). The only way I can continue developing is by deleting the .dart_tool folder, and wait until the project was built again. Obviously, this is quite disruptive concerning my workflow.

The trigger It is clear that it only happens when I'm editing HTML files (as in: Angular template files). I've tried reproducing it by creating a small project, with a similar setup and similar dependencies. But everything seemed to work as expected then. The best way to reproduce it, on my specific project, would be:

• Type in my_component.html: "<div [isLoading]="true">

[matanlurey]

/cc @natebosch @jakemac53

[vsmenon]

ping

@natebosch @jakemac53 @stereotype441 any ideas here? Not sure where to triage this.

Does a cache need to be cleared? Is that in the analyzer proper or in a build_runner worker?

[dotdotcommadot]

I'm currently testing to see if it has to do with having a bad circular dependency, in pubspec.yaml. Let's say we have a Project A which has a dependency on an external library called Project B. But Project B uses some services from Project A, so it depends on it as well. Then we get:

• Project A:
  • dependency on github.com:projectB.git
• Project B
  • dependency on github.com:projectA.git

Now, in development, I need Project A to have a dependency on a checked out version of Project B. (And this is the scenario where things go wrong, I think) So we get:

• Project A:
  • Dependency on github.com:projectB.git
  • Dependency Override on ../projectB
• Project B
  • Dependency on github.com:projectA.git

I'm starting to have a small feeling adding a dependency override to Project B solves this:

• Project A:
  • Dependency on github.com:projectB.git
  • Dependency Override on ../projectB
• Project B
  • Dependency on github.com:projectA.git
  • Dependency Override on ../projectA

Having a circular dependency isn't probably the best idea, anyways.

[dotdotcommadot]

Crap, I just got the error again.. Forget what I said :)

[jakemac53]

Hmmm, this probably is a result of the circular dependency in some form. We should support them at the build system level, but its possible there is an error in some other part of the toolchain or a bug in our implementation.

Are you manually specifying a module strategy by chance? Or using the default?

[dotdotcommadot]

No, we are using the default strategy.

[natebosch]

cc @scheglov

[scheglov]

We don't plan making fixes for task model. DDC migrating to Kernel, and for now has migrated to AnalysisDriver. You can try using a bleeding edge build of SDK.

[vsmenon]

@jmesserly

Is this still visible on 2.1? I believe DDC has migrated off the code @scheglov references above in the latest release.

[dotdotcommadot]

I have been working with 2.2.0-dev.0.0 for a while, and still run into this issue though...

[jmesserly]

@dotdotcommadot would you happen to have an update stack trace? DDC is calling into different Analyzer code now, so it's likely failing in a different location.