After upgrading to Ubuntu 11.10, git-svn started giving me a hard time.
Updates from the SVN master repository started to fail with error messages like this:
Byte order is not compatible at ../../lib/Storable.pm (autosplit into ../../lib/auto/Storable/_retrieve.al) line 380, 
  at /usr/share/perl/5.12/Memoize/Storable.pm line 21
Could not unmemoize function `lookup_svn_merge', because it was not memoized to begin with 
  at /usr/lib/git-core/git-svn line 3213
END failed--call queue aborted at /usr/lib/git-core/git-svn line 40.
Apparently, git-svn maintains cached meta information in 
.git/svn/.caches, which the Perl 
Storable.pm library choked on. I 
guess what happened is that Ubuntu 11.10 came with a more recent version of Perl and the Perl libraries,
and the new version of 
Storable.pm did not know how to handle data stored with older versions. Again, just a guess.
Discussions at 
http://lists.debian.org/debian-perl/2011/05/msg00023.html, 
http://lists.debian.org/debian-perl/2011/05/msg00026.html
and 
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=618875 suggest this may in fact a bug in the 
git-svn scripts, but I did
not venture to analyse the problem any further.
Anyway, the following took care of the problem for me:
  rm -rf .git/svn/.caches
Previous month: Click 
here.
 
Revision: r1.2 - 21 Dec 2011 - 11:35 - ClausBrod