Created attachment 369166 [details] build.log build.log attached
Created attachment 369168 [details] emerge --info '=dev-perl/glib-perl-1.301.0::gentoo'
Created attachment 369170 [details] emerge -pqv '=dev-perl/glib-perl-1.301.0::gentoo'
Created attachment 369172 [details] The ebuild environment file
The dependency is in place so I can only conclude that you forgot to run perl-cleaner after upgrading dev-lang/perl.
Sorry, it was my fail. ((