Steps to reproduce on Debian Sarge: 1. ls -l /dev/null 2. wget http://www.python.org/ftp/python/2.5/Python-2.5b2.tgz 3. tar xvzf Pyth* 4. cd Pyth* 5. ./configure 6. make 7. su 8. make test 9. ls -l /dev/null /dev/null goes from being a special character device to a normal file of length zero. The following command can be used instead of step 8 above to delete /dev/null ./python -c 'import ctypes.test.test_find' To recreate /dev/null: 1. su 2. rm /dev/null 3. mknod -m 666 /dev/null c 1 3 4. chown root:root /dev/null
Logged In: YES user_id=11105 Now, that is an 'interesting' bug. ctypes.util.find_library does execute shell commands that happen to have '/dev/null' in them, but it is completely unclear to me how one can overwrite /dev/null (even if root). Can you see anything that's wrong there (That code is not from me, and I'm not at all an expert in linux programming)? BTW, I cannot reproduce this on ubuntu with 'sudo ./python -c "import ctypes.test.test_find"'.
Logged In: YES user_id=1554504 Hey Thomas, that pointer is just what I needed :-) /dev/null was being deleted by gcc. Discussion at http://www.cs.helsinki.fi/linux/linux-kernel/2001-38/1503.html The attached patch fixed the problem on Debian Sarge and Ubuntu 6.06.
Logged In: YES user_id=11105 Scot, your patch is not correct because 'cmd' is never executed. However, I was able to reproduce the overwriting of /dev/null by calling 'ctypes.util.find_library' for a shared lib that does not exist. Attached is a new patch 'util.diff' which fixes the problem for me. Can you please verify that it also works for you? Thanks for finding the bug and locating the problem!
Logged In: YES user_id=1554504 Yes, not executing the command was one way to fix the bug :-) Thanks for catching that. I verified the new patch to work.
