1570536 - mozharness shouldn't install requests

Status: NEW

(Release Engineering :: General, task)

Description

[Mike Hommey [:glandium]]

testing/mozharness/scripts/fx_desktop_build.py contains:

                'virtualenv_modules': [
                    'requests==2.8.1',
                ],

But we have a version in tree that should be used instead. Interestingly, emptying the list fails with:

[task 2019-07-31T11:12:09.097Z] Traceback (most recent call last):
[task 2019-07-31T11:12:09.097Z]   File "/builds/worker/workspace/build/src/testing/mozharness/scripts/fx_desktop_build.py", line 133, in <module>
[task 2019-07-31T11:12:09.097Z]     fx_desktop_build = FxDesktopBuild()
[task 2019-07-31T11:12:09.097Z]   File "/builds/worker/workspace/build/src/testing/mozharness/scripts/fx_desktop_build.py", line 83, in __init__
[task 2019-07-31T11:12:09.097Z]     super(FxDesktopBuild, self).__init__(**buildscript_kwargs)
[task 2019-07-31T11:12:09.097Z]   File "/builds/worker/workspace/build/src/testing/mozharness/mozharness/mozilla/building/buildbase.py", line 632, in __init__
[task 2019-07-31T11:12:09.097Z]     self.create_virtualenv()
[task 2019-07-31T11:12:09.097Z]   File "/builds/worker/workspace/build/src/testing/mozharness/mozharness/base/python.py", line 432, in create_virtualenv
[task 2019-07-31T11:12:09.097Z]     self.package_versions(log_output=True)
[task 2019-07-31T11:12:09.097Z]   File "/builds/worker/workspace/build/src/testing/mozharness/mozharness/base/python.py", line 171, in package_versions
[task 2019-07-31T11:12:09.097Z]     + pip_freeze_output)
[task 2019-07-31T11:12:09.097Z] TypeError: cannot concatenate 'str' and 'NoneType' objects

Because get_output_from_command return None when a command (in that case, pip freeze) has an empty output with no error.