Re: [Matplotlib-users] latex problem

[Fernando P. <Fer...@co...>]

Joost van Evert wrote:
> Dear list,


>         /usr/local/lib/python2.4/site-packages/matplotlib/texmanager.py
>         in make_dvi(self, tex, force)
>             125         # dir and move it if necessary and then cleanup
>             126         if os.path.exists(dvibase):
>         --> 127             os.rename(dvibase, dvifile)
>             128             for fname in glob.glob(prefix+'*'):
>             129                 os.remove(fname)
>         
>         OSError: [Errno 18] Invalid cross-device link

This could be considered a matplolib bug, or a python one, depending on your 
perspective.  os.rename() doesn't work across partitions, which makes it 
(IMHO) worse than useless. You have to either protect on all uses against this 
exception, or use shutil.move(), which does work across partitions:

Definition:     shutil.move(src, dst)
Docstring:
     Recursively move a file or directory to another location.

     If the destination is on our current filesystem, then simply use
     rename.  Otherwise, copy src to the dst and then remove src.
     A lot more could be done here...  A look at a mv.c shows a lot of
     the issues this implementation glosses over.


So if you think that Python is OK in having such a useless os.rename, then 
it's a matplotlib bug (this is, after all, known os.rename behavior).  In the 
short term, though, matplotlib would be well advised to use only os.rename 
when doing renamings *known to be in the same directory*.  Anytime you use 
rename to actually move things, this problem can appear (and it's 
configuration-specific, hence impossible to detect during in-house testing).

Cheers,

f