I just upgraded from ubuntu 14.04 to ubuntu 15.04. Since then uploading attachments using the attachment plugin doesn't work anymore in ikiwiki. It prints a "failed!" message. Any idea what may be wrong here and how to fix it?

ikiwiki version 3.20141016.2

`/var/log/apache2/error.log`

gives this:

Died at `/usr/share/perl5/IkiWiki/CGI.pm line 497`.

> I think this is probably [[!debbug 786587]], which ikiwiki has worked around since 3.20150610
> ([[!debbug 786586]]). If so, then it is [[already fixed|done]], but not in the version
> you have. You could report an Ubuntu bug asking for
> [ikiwiki commit 7a52c87](http://source.ikiwiki.branchable.com/?p=source.git;a=commit;h=7a52c87a8c745577a50d6c9d134f62f9c5b26b0a)
> or
> [CGI.pm commit e4500cf](https://github.com/leejo/CGI.pm/commit/e4500cfb2de27660398c09bc860d1d9e499cb372)
> to be backported, although in practice bugs in universe packages are unlikely to get fixed
> in an Ubuntu stable release.
>
> To work around this, you might be able to `apt-get remove libcgi-pm-perl` and use the
> older version of CGI.pm that is shipped with Perl. --[[smcv]]

Thanks, I just opened a bug r[eport on launchpad](https://bugs.launchpad.net/ubuntu/+source/ikiwiki/+bug/1470391).
