Right now emerge.log only indicates that builds were started and finished successfully. What it doesn't indicate is when builds actually failed. Right now, you can mostly try to guess which builds failed because emerge failed, e.g.: 1625567754: Started emerge on: lip 06, 2021 12:35:54 1625567754: *** emerge --buildpkgonly --oneshot --ask --autounmask=n --dynamic-deps=n --keep-going --with-bdeps=y --quiet-build=n --regex-search-auto=y --verbose --buildpkg compiler-rt-sanitizers 1625567765: >>> emerge (1 of 1) sys-libs/compiler-rt-sanitizers-12.0.1_rc4 to / 1625567765: === (1 of 1) Cleaning (sys-libs/compiler-rt-sanitizers-12.0.1_rc4::/home/mgorny/git/gentoo/sys-libs/compiler-rt-sanitizers/compiler-rt-sanitizers-12.0.1_rc4.ebuild) 1625567765: === (1 of 1) Compiling/Packaging (sys-libs/compiler-rt-sanitizers-12.0.1_rc4::/home/mgorny/git/gentoo/sys-libs/compiler-rt-sanitizers/compiler-rt-sanitizers-12.0.1_rc4.ebuild) 1625568416: *** Finished. Cleaning up... 1625568416: *** exiting unsuccessfully with status '1'. 1625568416: *** terminating. What I would really like to see here is information that the build of compiler-rt-sanitizers failed.