Keep version in sync between MODULE.bazel and version.bzl

[tetromino]

Reminder to myself: after merging #385, we will need some sort of a diff test to keep the module version and the version.bzl version in sync; neither file can load the other - MODULE.bazel prohibits load statements.

[tetromino]

The natural way to do so would be to extract version from MODULE.bazel via buildozer:

cat MODULE.bazel | buildozer 'print version' '-:bazel_skylib'

Unfortunately, this means we need to depend on buildozer, and while this is easy enough to do via WORKSPACE, it fails with --experimental_enable_bzlmod:

error loading package '@gazelle~0.26.0~go_deps~com_github_bazelbuild_buildtools//api_proto': Unable to find package for @[unknown repo 'rules_proto' requested from @gazelle~0.26.0~go_deps~com_github_bazelbuild_buildtools]//proto:defs.bzl: The repository '@[unknown repo 'rules_proto' requested from @gazelle~0.26.0~go_deps~com_github_bazelbuild_buildtools]' could not be resolved: Repository '@rules_proto' is not visible from repository '@gazelle~0.26.0~go_deps~com_github_bazelbuild_buildtools'. and referenced by '@gazelle~0.26.0~go_deps~com_github_bazelbuild_buildtools//edit:go_default_library'

I believe that I'm hitting bazel-contrib/rules_go#3265

Alternatively, we could avoid the problem trivially if there were an official buildtools module in the central registery - but it doesn't exist yet.

Current work in progress is sitting at https://github.com/tetromino/bazel-skylib/tree/version_consistency a.k.a. #396

[fmeum]

@tetromino I just submitted a PR that should add support for go_proto_library to rules_go with Bzlmod: bazel-contrib/rules_go#3283. I manually verified that it can build buildozer.

[fmeum]

rules_go 0.34.0 is now available in the register and should support go_proto_library.

[tetromino]

rules_go 0.34.0 is now available in the register and should support go_proto_library.

0.34.0 was released in July. I think your fix is in 0.35.0, which isn't in the register yet :)

[fmeum]

Given the experimental status of rules_go's bzlmod support as well as the BCR, we decided to continuously push updates to it, modifying existing versions if necessary - so 0.34.0 is indeed what you want. That will of course change when the BCR and Bzlmod support in Bazel become more stable.

[tetromino]

Hmm. I've confirmed that 0.34.0 that got downloaded by bazel from BCR into my external/ dir does have the fix, but I'm still hitting the same error - Repository '@rules_proto' is not visible from repository '@gazelle~0.26.0~go_deps~com_github_bazelbuild_buildtools'

ERROR: /private/var/tmp/_bazel_$USER/b2b208390ac65027996afab7ba69d49e/external/gazelle~0.26.0~go_deps~com_github_bazelbuild_buildtools/edit/BUILD.bazel:3:11: error loading package '@gazelle~0.26.0~go_deps~com_github_bazelbuild_buildtools//build_proto': Unable to find package for @[unknown repo 'rules_proto' requested from @gazelle~0.26.0~go_deps~com_github_bazelbuild_buildtools]//proto:defs.bzl: The repository '@[unknown repo 'rules_proto' requested from @gazelle~0.26.0~go_deps~com_github_bazelbuild_buildtools]' could not be resolved: Repository '@rules_proto' is not visible from repository '@gazelle~0.26.0~go_deps~com_github_bazelbuild_buildtools'. and referenced by '@gazelle~0.26.0~go_deps~com_github_bazelbuild_buildtools//edit:go_default_library'
ERROR: Analysis of target '//tests:bazel_skylib_version_consistency_test' failed; build aborted:

[tetromino]

Ah, I now understand the problem: I also need bazel-contrib/bazel-gazelle#1331

Time for git_override.

[fmeum]

Gazelle 0.26.0 should have the fix, but it was updated in place so you might need to clean.

[alexeagle]

Why don't you just have git archive stamp the version number for you? Then you don't need any commits to the repo nor having version numbers in multiple places? "stamping" also means any commit is releasable (the principle of continuous delivery)

(the template suggests it here https://github.com/bazel-contrib/rules-template/blob/main/.gitattributes#L12-L14
and here's what the starlark code looks like https://github.com/bazel-contrib/bazel-lib/blob/main/tools/version.bzl)