Ebuild passes MAKEOPTS to jam, which can contain unsupported switches (jam is not make). The ebuild has a sed hack that assumes the only thing that would be in MAKEOPTS is -j. src_compile() { local jamopts=$(echo "${MAKEOPTS}" | sed -ne "/-j/ { s/.*\(-j[0-9]\+\).*/\1/; p }") jam -dx -q ${jamopts} || die "jam failed" } My suggestion is to remove the MAKEOPTS reference altogether. Reproducible: Always Steps to Reproduce: 1. Put something besides -j in MAKEOPTS (example: MAKEOPTS="-j 1 -l 0.7"). 2. emerge glest Actual Results: >>> Compiling source in /var/tmp/portage/games-strategy/glest-3.2.2/work/glest-source-3.2.2 ... Invalid option: -l
fixed.