[Python-Dev] test_sys failures (original) (raw)

Guido van Rossum guido at python.org
Tue Jan 8 05:44:19 CET 2008

On Dec 21, 2007 12:05 AM, Nick Coghlan <ncoghlan at gmail.com> wrote:

Guido van Rossum wrote: > When I build from scratch and run most tests (regrtest.py -uall) I get > some strange failures with testsys.py: > > test testsys failed -- Traceback (most recent call last): > File "/usr/local/google/home/guido/python/py3kd/Lib/test/testsys.py", > line 302, in test43581 > self.assertEqual(sys.stdout.encoding, sys.stderr.encoding) > AssertionError: 'ascii' != 'ISO-8859-1' > > The same test doesn't fail when run in isolation. > > Interestingly, I saw this with 2.5 as well as 3.0, but not with 2.6! > > Any ideas?

It looks like the chunk of code in TextIOWrapper might be getting different answers when trying to work out the encoding for stdin and stderr (not that I can see how that would happen...). Or maybe there is some way that testsys could be seeing the temporary 'stderr' entry that is put in place until the io module is available? What do you get for stdin/stdout/stderr.encoding at the interactive prompt? On Ubuntu, I get UTF-8 for all of them in both 3.0a2 and 2.5.1, but I'm not seeing the problem, either. Other values of possible interest: os.deviceencoding(1) os.deviceencoding(2) locale.getpreferredencoding() Another possibility would be to throw some debugging code into io.py to print out the encoding name to stderr when file is 1 or 2.

No answers yet, but a clue, and anyone on OSX should now be able to reproduce this (with 2.5, 2.6 or 3.0) as follows:

./python ./Lib/test/test_sys.py | cat

That is, the problem happens when stdout is redirected to a pipe (or a file).

-- --Guido van Rossum (home page: http://www.python.org/~guido/)

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