Executing python file, sys.path is replaced rather than inserted

[nedbat]

Originally reported by Anonymous

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In coverage/execfile.py the current python module search path sys.argv is replaced rather inserted with the generated module path. This causes problems using coverage in a zc.buildout environment where sys.path is used to point to local installed eggs.

If required to understand the issue, I can try to come up with a patch.

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• Bitbucket: https://bitbucket.org/ned/coveragepy/issue/142
• This issue had attachments: coverage.patch. See the original issue for details.

[nedbat]

Original comment by Daniele Nicolodi (Bitbucket: daniele, GitHub: daniele)

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Something like this may work (untested)

[nedbat]

I don't understand the issue: can you explain why your patch works and the original code doesn't? What does zc.buildout do that other code doesn't do? What is the symptom of the problem?

[nedbat]

Original comment by Anonymous

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I have no idea about zc.buildout but this patch fixes a practical issue when running unittest and coverage.

Before the patch:

$ python -m unittest my.module
.....
----------------------------------------------------------------------
Ran 5 tests in 0.001s

OK


$ python -m coverage run -m unittest my.module
Coverage.py warning: No data was collected.
Traceback (most recent call last):
  File "/usr/lib64/python2.7/unittest/__main__.py", line 12, in <module>
    main(module=None)
  File "/usr/lib64/python2.7/unittest/main.py", line 94, in __init__
    self.parseArgs(argv)
  File "/usr/lib64/python2.7/unittest/main.py", line 149, in parseArgs
    self.createTests()
  File "/usr/lib64/python2.7/unittest/main.py", line 158, in createTests
    self.module)
  File "/usr/lib64/python2.7/unittest/loader.py", line 128, in loadTestsFromNames
    suites = [self.loadTestsFromName(name, module) for name in names]
  File "/usr/lib64/python2.7/unittest/loader.py", line 91, in loadTestsFromName
    module = __import__('.'.join(parts_copy))
ImportError: No module named my

After the patch:

$ python -m coverage run -m unittest my.module
.....
----------------------------------------------------------------------
Ran 5 tests in 0.001s

OK

Previously I had to add '.' to PYTHONPATH in order to get unittest and coverage to cooperate.

$ env PYTHONPATH=. python -m coverage run -m unittest my.module
.....
----------------------------------------------------------------------
Ran 5 tests in 0.001s

OK

[nedbat]

This was fixed in October of 2011, in changeset 781082764b17 (bb).