On Sat, 03 Aug 2013 19:04:21 -0700, Eli Bendersky <eli...@gmail.com> wrote: > On Sat, Aug 3, 2013 at 6:57 PM, R. David Murray <rdmur...@bitdance.com> wrote: > > On Sat, 03 Aug 2013 16:47:37 -0700, Eli Bendersky <eli...@gmail.com> wrote: > >> On Sat, Aug 3, 2013 at 4:36 PM, Eli Bendersky <eli...@gmail.com> wrote: > >> > Hi All, > >> > > >> > Today the issue of cross-test global env dependencies showed its ugly > >> > head again for me. I recall a previous discussion > >> > (http://mail.python.org/pipermail/python-dev/2013-January/123409.html) > >> > but there were many more over the years. > >> > > >> > The core problem is that some tests modify the global env > >> > (particularly importing modules) and this sometimes has adverse > >> > effects on other tests, because test.regrtest runs all tests in a > >> > single process. In the discussion linked above, the particular culprit > >> > test__all__ was judged as a candidate to be moved to a subprocess. > >> > > >> > I want to propose adding a capability to our test harness to run > >> > specific tests in subprocesses. Each test will have some simple way of > >> > asking to be run in a subprocess, and regrtest will concur (even when > >> > running -j1). test__all__ can go there, and it can help solve other > >> > problems. > >> > > >> > My particular case is trying to write a test for > >> > http://bugs.python.org/issue14988 - wherein I have to simulate a > >> > situation of non-existent pyexpat. It's not hard to write a test for > >> > it, but when run in tandem with other tests (where C extensions loaded > >> > pyexpat) it becomes seemingly impossible to set up. This should not be > >> > the case - there's nothing wrong with wanting to simulate this case, > >> > and there's nothing wrong in Python and the stdlib - it's purely an > >> > artifact of the way our regression suite works. > >> > > >> > Thoughts? > >> > > >> > Eli > >> > >> FWIW the problem is also discussed here: > >> http://bugs.python.org/issue1674555, w.r.t. test_site > > > > Can't you just launch a subprocess from the test itself using > > script_helpers? > > > > I can, but such launching will be necessarily duplicated across all > tests that need this functionality (test_site, test___all__, etc). > Since regrtest already has functionality for launching whole > test-suites in subprocesses, it makes sense to reuse it, no?
In the case of test_site and test___all___ we are talking about running the entire test file in a subprocess. It sounds like you are only talking about running one individual test function in a subprocess, for which using script_helpers seems the more natural solution. --David _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
