mbland / bzlmod-local-module-bug

Bazel local_path_override bug example

Bazel local_path_override bug example

This reproduces a problem with using a Bazel module within the same repository that calls load() on a top-level target. The problem happens with both:

• 7.1.1: The most recent official release
• 8.0.0-pre.20240415.1: The most recent prerelease build

Use bazelisk and tweak .bazelversion to switch between the two.

third_party/vendored_module is a trimmed down example based on a vendored copy of the bazel_skylib v1.5.0 distribution used by my project. This example module builds successfully with both Bazel versions in its own directory, both with and without bzlmod.

Without bzlmod

Configured via local_repository in WORKSPACE:

% bazel build --nobuild --enable_bzlmod=false //...

INFO: Analyzed 0 targets (1 packages loaded, 0 targets configured).
INFO: Found 0 targets...
INFO: Elapsed time: 0.099s, Critical Path: 0.00s
INFO: 0 processes.
INFO: Build completed successfully, 0 total actions

With bzlmod

Configured via bazel_dep and local_path_override in MODULE.bazel:

% bazel build --nobuild --enable_bzlmod=true //...

WARNING: Target pattern parsing failed.
ERROR: Skipping '//...': error loading package under directory '': error loading package 'third_party/vendored_module': cannot load '//:top_level_target.bzl': no such file
ERROR: error loading package under directory '': error loading package 'third_party/vendored_module': cannot load '//:top_level_target.bzl': no such file
INFO: Elapsed time: 0.054s
INFO: 0 processes.
ERROR: Build did NOT complete successfully

local_path_override and the bzmlod mechanism seem to assume the module will not reside within the same repo. The WORKSPACE or MODULE.bazel repository boundary marker files don't appear to have an effect. (Neither do artificially added REPO.bazel or WORKSPACE.bazel files.)