[Bug]: update_pnpm_lock fails under Bzlmod, retry fixes it

[alexeagle]

What happened?

Under bzlmod, update_pnpm_lock fails on the first attempt.

Version

HEAD

How to reproduce

In rules_js,

1. cd e2e/npm_translate_lock
2. modify package.json, like "semver": "7.5.4"

then bazel build ... gives an error:

~/Projects/rules_js/e2e/npm_translate_lock$ bazel build --enable_bzlmod ...
Starting local Bazel server and connecting to it...
ERROR: Skipping '...': error loading package under directory '': error loading package '': at /shared/cache/bazel/user_base/3b36aba3ddc6cb653f7aaaed8bb07c4d/external/aspect_rules_js~override~npm~npm/defs.bzl:40:6: Unable to find package for @aspect_rules_js~override~npm~npm__semver__registry.npmjs.org_semver_7.5.4__links//:defs.bzl: The repository '@aspect_rules_js~override~npm~npm__semver__registry.npmjs.org_semver_7.5.4__links' could not be resolved: Repository '@aspect_rules_js~override~npm~npm__semver__registry.npmjs.org_semver_7.5.4__links' is not defined.

Simply running the same bazel build command again fixes it.

Any other information?

No response

[alexeagle]

Adding some print debugging shows that the module extension isn't executed the way we thought. We call npm_translate_lock but it is non-blocking, the module_ctx.read(attr.pnpm_lock) later in extensions.bzl is already evaluated before we write the changed pnpm-lock.yaml back to the disk. I think this is fixable, but I'm not exactly sure how, and anyway I don't think we have time to prioritize it right now.

[alexeagle]

Got some design feedback from the Bazel team: https://bazelbuild.slack.com/archives/C014RARENH0/p1705451482052209

[jbedard]

Support for this has been removed (bzlmod and workspace) in 2.x: ffd4583