go_deps package visibility

[bstoll]

I am trying to use the go_deps extension to import dependencies from go.mod files and am running into a case that works with Go's dependency resolution but does not work so well with Gazelle/Bazel.

I have an example repository at https://github.com/bstoll/import-visibility-parent and https://github.com/bstoll/import-visibility-child. The parent depends on the child, which depends on the parent. In this scenario, Go's module system allows this to work:

[bstoll@bstoll-ct:parent]$ go run github.com/bstoll/import-visibility-parent/cmd
Hello from main v2
Hello from child v2
Hello from parent v2

However, with Bazel this fails:

[bstoll@bstoll-ct:parent]$ bazel run //cmd:cmd
ERROR: no such package '@@[unknown repo 'com_github_bstoll_import_visibility_parent' requested from @@gazelle++go_deps+com_github_bstoll_import_visibility_child]//': The repository '@@[unknown repo 'com_github_bstoll_import_visibility_parent' requested from @@gazelle++go_deps+com_github_bstoll_import_visibility_child]' could not be resolved: No repository visible as '@com_github_bstoll_import_visibility_parent' from repository '@@gazelle++go_deps+com_github_bstoll_import_visibility_child'
ERROR: /usr/local/google/home/bstoll/.cache/bazel/_bazel_bstoll/2e7b003f152a6b9486f33cb666da68af/external/gazelle++go_deps+com_github_bstoll_import_visibility_child/BUILD.bazel:6:11: no such package '@@[unknown repo 'com_github_bstoll_import_visibility_parent' requested from @@gazelle++go_deps+com_github_bstoll_import_visibility_child]//': The repository '@@[unknown repo 'com_github_bstoll_import_visibility_parent' requested from @@gazelle++go_deps+com_github_bstoll_import_visibility_child]' could not be resolved: No repository visible as '@com_github_bstoll_import_visibility_parent' from repository '@@gazelle++go_deps+com_github_bstoll_import_visibility_child' and referenced by '@@gazelle++go_deps+com_github_bstoll_import_visibility_child//:import-visibility-child'
ERROR: Analysis of target '//cmd:cmd' failed; build aborted: Analysis failed
INFO: Elapsed time: 0.783s, Critical Path: 0.00s
INFO: 1 process: 1 internal.
ERROR: Build did NOT complete successfully
ERROR: Build failed. Not running target

The issue seems to be that the parent package is not made available as com_github_bstoll_import_visibility_parent to go_deps. There are some knobs I found that force this into working by adding this to MODULE.bazel:

go_deps_dev = use_extension("@bazel_gazelle//:extensions.bzl", "go_deps", dev_dependency = True)
go_deps_dev.gazelle_override(
    directives = [
        "gazelle:resolve go github.com/bstoll/import-visibility-parent @import-visibility-parent//:import-visibility-parent",  # keep
    ],
    path = "github.com/bstoll/import-visibility-child",
)
inject_repo(go_deps_dev, "import-visibility-parent")

I am not sure if this is an ideal solution to this problem. While unwinding this is probably ideal, can the go_deps extension make the parent repository available for children to import from?

[fmeum]

Fixing this may be as easy as running the code in this else block unconditionally:

bazel-gazelle/internal/bzlmod/go_deps.bzl

Line 446 in 227f6ac

# Register this Bazel module as providing the specified Go module. It participates

Could you give that a try?