Nicolas Vigier:
Ok, we can have a test rebuilding several times the files that are most likely to become non deterministic. However it would be better if we can find some way to trigger those non-deterministic builds with only two builds. Maybe we can try something like this :
a library that we put in LD_PRELOAD as a wrapper on readdir to return directory entries in random order instead of inodes number, so it's more likely to be different on each build.
a python library that we put in PYTHONPATH, to override dict.iterkeys to return keys in random order. If I understand ticket #10159 correctly, it was caused by iterkeys returning keys in the same order most of the time, but not all the times.
I would suggest using reverse order instead of random order. Random order has the probability of being just like the original order. For readdir(3), have a look at: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=719845#39