libsdl-1.2.15-r4 is EAPI=5 and still using epause, which has apparently been undefined since EAPI=3. I see -r4 bumped all the way from EAPI-2 to EAPI-5, and it was just added yesterday, so the oversight is understandable. (Given that it doesn't block merging only emit that ugly warning, I downgraded to trivial severity.)
and a non-maintainer rev bump as well. fixed.