To enable pcre-jit support in nginx requires libpcre-8.20 or greater to be have been installed with the jit USE flag enabled. This nuance is not expressed in the ebuild. pcre-jit? ( >=dev-libs/libpcre-8.20[jit] )
this has been fixed by upstream in 1.2.2/1.3.3
oops, wrong bug :-) this has been fixed in the ebuilds