I downloaded the post-review script from the Subversion repository at revision 1990 and attempted to use it to submit a change to our server which is running a nightly snapshot from last December. The post-review script exited with an error when it attempted to generate the diff file from Perforce. When I enabled debugging and attempted to run the failing diff command, I discovered that the temporary file that was being used to hold the previous version of the file had the odd permissions of -w-------. After some poking around, I discovered that the _write_file method had been updated in revision 1988 to explicitly call os.chmod(tmpfile, stat.S_IWRITE). If I change the call to os.chmod(tmpfile. stat.S_IREAD | stat.S_IWRITE), then I am able to successfully post changes for review. I have a attached a patch file that contains the described one line change.
Thanks. Sorry about the breakage. We generally prefer that diffs be uploaded to http://reviews.review-board.org/, but this is simple enough where I'll take this here this time. Fixed in r1991.