This is a repository to reproduce an issue in bazel. The companion-repository bazel-issue-sw shows no error. This repository will not work though.
Usage:
bazel build -c dbg //:mytest
bazel coverage -c dbg --combined_report=lcov --instrumentation_filter="@sw_repo//:funclib" --action_env=COVERAGE_GCOV_OPTIONS=-b //:mytest
The second command will fail with WARNING: There was no coverage found. Of course, there IS coverage data present. But the data is excluded by the default coverage collector shell script because bazel's clone of the software repository is located below folder external. All external's are excluded, which is a good thing, unless the external is the SUT and accordingly instrumented.
Thus the following command
genhtml --branch-coverage --output html "$(bazel info output_path)/_coverage/_coverage_report.dat"
also fails with genhtml: ERROR: no valid records found in tracefile.
These problems do not appear if we test this locally in the bazel-issue-sw repository.
There was a solution for this problem in this pull request but then the feature got removed again from bazel 6.0.0 release. As of now as a workaround for this problem, we can use an intermediate version, e.g. 7.0.0-pre.20221102.3.
Please note that genhtml is not able to find the path if we do not create a symlink into the bazel execution runtime folder.
Usage:
USE_BAZEL_VERSION=7.0.0-pre.20221102.3 bazel build -c dbg //:mytest
USE_BAZEL_VERSION=7.0.0-pre.20221102.3 bazel coverage -c dbg --combined_report=lcov --instrumentation_filter="@sw_repo//:funclib" --action_env=COVERAGE_GCOV_OPTIONS=-b //:mytest
[ -L external ] && rm external
ln -s $(bazel info execution_root)/external external
genhtml --branch-coverage --output html "$(bazel info output_path)/_coverage/_coverage_report.dat"