Dear Danny, You asked on guix-devel since when Mesa is not reproducible: at least since v1.1.0.
git --no-pager log v1.1.0 -1 --format='%H' d62c9b2671be55ae0305bebfda17b595f33797f2 guix time-machine --commit=d62c9b2671be55ae0305bebfda17b595f33797f2 \ -- build mesa guix time-machine --commit=d62c9b2671be55ae0305bebfda17b595f33797f2 \ -- build mesa --no-grafts --check -K --8<---------------cut here---------------start------------->8--- guix build: error: derivation `/gnu/store/wsp9wf83bbsmz8x061rhqndx05zmjff0-mesa-19.3.4.drv' may not be deterministic: output `/gnu/store/2mf0clz9w64diy0kz11qcs4q5wg9hc6z-mesa-19.3.4' differs from ?/gnu/store/2mf0clz9w64diy0kz11qcs4q5wg9hc6z-mesa-19.3.4-check? --8<---------------cut here---------------end--------------->8--- And the differing files are: - lib/dri/iris_dri.so - lib/dri/nouveau_drv_video.so - lib/libvulkan_radeon.so - lib/vdpau/libvdpau_nouveau.so.1.0.0 All the best, simon