Error: post-commit hook failed (exit code 255) with no output

In subversion I was getting the error "post-commit hook failed (exit code 255) with no output" after trying to configure my post-commit hook to send email notifications. At first I thought the problem must have been related to the mailer, but I ran the mail command manually and it worked fine. Eventually I figured out that the problem was that the hooks/post-commit file hadn't been marked executable. So it was a simple chmod +x to fix the problem.

How To Set Cron to Run Every 5 Minutes

Thanks to this handy document How To Set Cron to Run Every 5 Minutes I now my crontab configured so that my jj5-test repo gets updated every five minutes. It's the sort of thing I generally do in a post-commit hook, but in this case that won't work owing to the way the servers are configured (the files are in my account and not owned by the www-data user the commit-hook runs as).

So to configure cron I issued the command:

 $ crontab -e

And then to update my svn working copy:

# m h  dom mon dow   command
*/5 * * * * cd /home/jj5/web/test && svn update > /dev/null