While I was on vacation, my CommonsHelper stopped working for direct
upload. Here's what happens:

* CommonsHelper (PHP) downloads an image to /tmp
* CommonsHelper invokes upload bot written in Perl
* Perl dies:
Can't open file /tmp/chHHaikY-dir/dummy.jpg : No such file or
directory at /opt/ts/perl/5.10/lib/vendor_perl/5.10/LWP/UserAgent.pm
line 394

However, the file exists at that point in time (this one still does on
wolfsbane, feel free to check), and is readable for everyone.

Any idea what's going on?