Building libmypaint fails consistently when dev-perl/XML-Parser is not installed, but XML-Parser is not listed as (build-time-)dependency. Building with XML-Parser being installed works just as consistently across several machines.
Please provide the full build.log and emerge —-info.
*facepalm* Sometimes optimizing your filesystem layout for minimum flash wear can go too far and yield interesting results like this: I have my core system on this machine residing on an overlayfs consisting of squashfs with tmpfs on top. Now if the squashfs is created from an inconsistent system state to begin with (incomplete file system image), you might end up with the world set indicating that dev-perl/XML-Parser is installed while in fact it is not. Combine that with not updating the underlying squashfs before reboot due to a broken script and you end up with consistent behaviour across reboots: first emerge of libmypaint fails due to intltool not finding XML::Parser modules, subsequently after emerging XML-Parser it works. Until the next reboot of course, where we're back to square one again. So what looked like a missing dependency (which incidentally was only indirect to begin with, as dev-util/intltool depends on dev-perl/XML-Parser already) turns out to be perfectly okay IF YOUR SYSTEM IS SANE... Should have checked this before filing a bug. So, this bug can be closed as invalid without further action. Sorry for the disturbance...
No worries at all. Just an FYI: this sometimes happens with Perl upgrades and is really unfortunate. perl-cleaner --all is a good idea if this happens, but I understand in your case, it sounds like it was something else. Just glad you figured it out! Give me a shout if you hit any problems.
