I've attached a (slightly) modded ebuild that builds perl regexp support based on the perl and -perl use flags. I see this as a slightly better alternative then actually not supporting it by default. Reproducible: Always Steps to Reproduce: 1.emerge grep 2.perl regexp support disabled by default 3.
Created attachment 31531 [details] Grep ebuild that supports perl USE flags
This problem has been mentioned previously, about 2 years ago. http://bugs.gentoo.org/show_bug.cgi?id=1638 Though I don't see the reason as to why no correction had been taken.
*** This bug has been marked as a duplicate of 51215 ***