checking OpenGL... no
checking Mesa... no
checking Mesa with pthreads... no
configure: error: You need GL or MesaGL libraries
!!! ERROR: x11-libs/gtkglarea-1.99.0 failed.
!!! Function econf, Line 449, Exitcode 1
!!! econf failed
!!! If you need support, post the topmost build error, NOT this status message.