Subversion 1.5 adds some fields to the entries file in the working copy 
administrative area. As a result of this, the way in which setuptools 
checks the entries files results in a raised exception. Having read the 
spec for the entries file, the issue can be fixed simply by looking for 
version 8 or version 9 in the opening of the entries file. I've attached a 
patch that does this. I've tested it extensively locally (been using it 
for months).