Reduce dependencies for generated wrapper script.

[adam-azarchs]

🚀 feature request

Relevant Rules

py_binary, py_test

Description

For situations like remote execution or executing in a docker container for hermiticity and reproducibility, it's helpful to keep the container image size to an absolute minimum. The bazel-generated wrapper script, which at least at the moment runs with the system-provided python3, imports a bunch of modules which are not present in the python3-minimal package in the debian ecosystem.

Describe the solution you'd like

The imports

import shutil
import tempfile
import zipfile

are only required if IsRunningFromZip is True. They shouldn't be imported if it isn't.

They're imported by the template here.

The offending imports could be guarded by

if %is_zipfile%:

in the template.

Describe alternatives you've considered

#42 would also solve this problem, mostly. If you have a lot of unit tests to run then the time it takes to process those often-unnecessary imports can add up.

[hrfuller]

The python binary shim template is part of bazelbuild/bazel. Not this repository. I recommend you open an issue in the repo.