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Bazel: source mode mocks fail analysis with the race detector on rules_go 0.63 #322
Description
Actual behavior With rules_go 0.63.0, every gomock target in source mode fails analysis when the race detector is enabled:
Error in fail: race instrumentation can't be enabled when cgo is disabled. Check that pure is not set to "off" and a C/C++ toolchain is configured.
The traceback goes from _gomock_source_impl through go_context(ctx, include_deprecated_properties = False) to validate_mode. Archive mode is not affected.
Expected behavior Builds and tests with --@io_bazel_rules_go//go/config:race work for targets that depend on source mode mocks.
To Reproduce Steps to reproduce the behavior
- In
bazel/MODULE.bazel, raise rules_go to 0.63.0. This resolves gazelle 0.51.3, whose tools needgo 1.25.0inbazel/go.mod. - In
bazel/, runbazel test --@io_bazel_rules_go//go/config:race //.... - All
_gomock_sourcetargets intests/sourceandtests/source_with_importpathfail with the error above.
Additional Information
- gomock mode (reflect or source): source, through the Bazel
gomockrule - gomock version or git ref: main (d8c3a2a)
- golang version: 1.25.0, with rules_go 0.63.0 and Bazel 9.2.0 on Linux amd64
Cause
Since rules_go 0.62, go_context forces pure mode for rules that do not declare a C/C++ toolchain, and pure mode cannot be combined with race. _gomock_source reads the target Go configuration through _go_context_data, so it sees race enabled, but it declares only the Go toolchain. rules_go 0.63 added an opt-out and documents it for this kind of rule: "Rules that only use the Go SDK or generate Go sources can use rule, declare only the @io_bazel_rules_go//go:toolchain toolchain, and call go_context(ctx, maybe_needs_cc_toolchain = False)." From the rules_go sources, 0.62 forces pure mode the same way, while 0.61 and older do not.
Proposed fix
Call go_context(ctx, include_deprecated_properties = False, maybe_needs_cc_toolchain = False) in _gomock_source_impl. The parameter exists since rules_go 0.61 and takes effect from 0.63, so bazel/MODULE.bazel would require rules_go 0.63.0. A CI step that runs the Bazel tests with --@io_bazel_rules_go//go/config:race catches regressions. A PR with this change follows; locally the Bazel tests pass with and without the race flag.
Activity