There is an issue where pecl-bbcode-1.0.3_beta1 fails to build with slotted PHP due to the PHP_EXT_S not being set correctly to S as it's being defined after the inherit. I've attached a patch as well as bumped the ebuild to EAPI 4, added 5.4 as a valid slot (as it builds successfully) and done some general house cleaning. Full source can be found here: https://github.com/jamiel/gentoo-overlay/tree/master/dev-php/pecl-bbcode
Created attachment 301125 [details] pecl-bbcode-1.0.3_beta1-r1.ebuild.patch
Thanks for the report. I fixed this now using something like your patch.