You receive this bug because this package does not respect my system's RANLIB (x86_64-pc-linux-gnu-ranlib) and calls directly /usr/bin/ranlib The possible solutions to fix this issue are: 1)Fix the buildsystem, if you can; 2)inherit toolchain-funcs and use tc-export RANLIB 3)inherit toolchain-funcs and use emake RANLIB="$(tc-getRANLIB)" From the build log: ranlib libcojets.a
04 Jun 2013; Sébastien Fabbro <bicatali@gentoo.org> cernlib-montecarlo-2006-r3.ebuild: Respect user toolchain (bug #468192)