py_test allows non-hermetic unspecified dependencies

[mdvorsky]

Description of the problem / feature request:

py_test allows the source file to import an unspecified dependency

Bugs: what's the simplest, easiest way to reproduce this bug? Please provide a minimal example if possible.

$ cat WORKSPACE
$ cat BUILD
py_test(
    name = "test",
    srcs = ["test.py"]
)
$ cat test.py
import import_test
print('pass')
$ cat import_test.py
$ bazel test test
...
//:test                            PASSED in 0.1s

What operating system are you running Bazel on?

macOS Mojave 10.14.5

What's the output of bazel info release?

release 0.25.3-homebrew

Have you found anything relevant by searching the web?

No.

[brandjon]

Thanks for the report. This is #7091. In order to fix it we'd have to inject some sys.path manipulation logic into the initialization of the user Python process (not the stub script), or generate a dummy directory holding only a copy of the main file and nothing else, or both.

[mdvorsky]

@brandjon the linked issue #7091 is now reported fixed in Bazel 1.2.1, but the above repro still works even with that version.

$ bazel version
Build label: 1.2.1-homebrew
Build target: bazel-out/darwin-opt/bin/src/main/java/com/google/devtools/build/lib/bazel/BazelServer_deploy.jar
Build time: Wed Nov 27 03:51:56 2019 (1574826716)
Build timestamp: 1574826716
Build timestamp as int: 1574826716

$ bazel test test
...
//:test                                                                  PASSED in 0.3s