fix: Exclude external directory when generating python report (#2136)
This PR will reduce the time it take to run `bazel coverage`
*Before this fix,*
```
bazel coverage --cache_test_results=no //...
Elapsed time: 7.054s, Critical Path: 6.87s
```
[lcov --list
bazel-out/_coverage/_coverage_report.dat](https://github.com/user-attachments/files/16681828/lcov.log)
*After*
```
bazel coverage --cache_test_results=no //...
Elapsed time: 2.474s, Critical Path: 1.18s
$ lcov --list bazel-out/_coverage/_coverage_report.dat
Reading tracefile bazel-out/_coverage/_coverage_report.dat
|Lines |Functions |Branches
Filename |Rate Num|Rate Num|Rate Num
================================================================================
[/home/ewianda/.cache/bazel/_bazel_ewianda/da4b4cc49e0e621570c9e24d6f1eab95/execroot/_main/bazel-out/k8-fastbuild/bin/benchsci/ml/nlp/]
test_tokenizer_stage2_bootstrap.py | 6.0% 250| - 0| - 0
[benchsci/]
devtools/python/pytest_helper.py |90.5% 21| - 0| - 0
ml/nlp/test_tokenizer.py | 100% 13| - 0| - 0
ml/nlp/tokenizer.py |61.8% 76| - 0| - 0
================================================================================
Total:|26.1% 360| - 0| - 0
```
Related to https://github.com/bazelbuild/rules_python/issues/1434
---------
Co-authored-by: aignas <240938+aignas@users.noreply.github.com>diff --git a/CHANGELOG.md b/CHANGELOG.md
index f703269..2e29017 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -29,6 +29,8 @@
### Fixed
* (gazelle): Fix incorrect use of `t.Fatal`/`t.Fatalf` in tests.
+* (toolchain) Omit third-party python packages from coverage reports from
+ stage2 bootstrap template.
### Added
* Nothing yet
diff --git a/python/private/stage2_bootstrap_template.py b/python/private/stage2_bootstrap_template.py
index 29f59d2..f66c28b 100644
--- a/python/private/stage2_bootstrap_template.py
+++ b/python/private/stage2_bootstrap_template.py
@@ -364,6 +364,14 @@
# Pipes can't be read back later, which can cause coverage to
# throw an error when trying to get its source code.
"/dev/fd/*",
+ # The mechanism for finding third-party packages in coverage-py
+ # only works for installed packages, not for runfiles. e.g:
+ #'$HOME/.local/lib/python3.10/site-packages',
+ # '/usr/lib/python',
+ # '/usr/lib/python3.10/site-packages',
+ # '/usr/local/lib/python3.10/dist-packages'
+ # see https://github.com/nedbat/coveragepy/blob/bfb0c708fdd8182b2a9f0fc403596693ef65e475/coverage/inorout.py#L153-L164
+ "*/external/*",
],
)
cov.start()
