How to debug berry crash? Are there source maps?

[stefansundin]

Hello,

I'm trying to debug a crash we are experiencing in our CI. I have a suspicion what the problem is, but I want to gather more information before I file a bug report.

Are there source maps available for berry? Right now the stack trace is pretty useless so I'm having trouble pinpointing where the source code is. I think it might even be in a dependency.

Alternatively, is there a way to run an un-minified berry?

Here's my stack trace if anyone wants to help me figure out the problem (version 4.0.2):

Error: spawn ETXTBSY
    at ChildProcess.spawn (node:internal/child_process:421:11)
    at Object.spawn (node:child_process:761:9)
    at ZY (/app/.yarn/releases/yarn-4.0.2.cjs:9:51927)
    at RE.implementation (/app/.yarn/releases/yarn-4.0.2.cjs:159:1348)
    at RE.exec (/app/.yarn/releases/yarn-4.0.2.cjs:165:1414)
    at RE.run (/app/.yarn/releases/yarn-4.0.2.cjs:165:1585)
    at ace (/app/.yarn/releases/yarn-4.0.2.cjs:165:7428)
    at async Bot (/app/.yarn/releases/yarn-4.0.2.cjs:167:16)
    at async u (/app/.yarn/releases/yarn-4.0.2.cjs:167:147)
    at async vot (/app/.yarn/releases/yarn-4.0.2.cjs:168:14)

We're seeing it happen in CircleCI when running yarn workspaces focus --production when building our docker container.

Would love to learn how to debug this. Thanks!

Edit: I think the bug is similar to this one: browserstack/browserstack-runner#217

[stefansundin]

Okay, I managed to fix this. We have been pinning the remote docker version in CircleCI and apparently it is super old now.

      # DO NOT USE THIS!
      - setup_remote_docker:
          version: 20.10.24
          docker_layer_caching: true

So if anyone else is doing this just remove version or use version: default.

From https://circleci.com/docs/building-docker-images/#docker-version

To use the current deprecated version, Docker 20, use 20.10.24

That solved the issue, but perhaps there's an actual bug and this old docker version hits a race condition?

I'm still interested in learning if there are ways to debug berry and how to get a better stack trace.

[merceyz]

You're probably running into nodejs/node#48444 so not a bug in Yarn.

You can use set version from sources to get a non-minified version of Yarn:

yarn set version from sources --no-minify --branch "@yarnpkg/cli/4.0.2"

If you want source maps you'll have to clone the repo and build Yarn with

yarn build:cli --no-minify --source-map

then update your project .yarnrc.yml to point to the bundle in ./packages/yarnpkg-cli/bundles/yarn.js.