$ git clone -n https://src.fedoraproject.org/rpms/libdrm.git /var/lib/mock/f39-build-1578478-37997/root/chroot_tmpdir/scmroot/libdrm
Cloning into '/var/lib/mock/f39-build-1578478-37997/root/chroot_tmpdir/scmroot/libdrm'...
$ git fetch origin 8a94a7817d151aeac6abf90796302c2e785c0cc6:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libdrm
 * [new ref]         8a94a7817d151aeac6abf90796302c2e785c0cc6 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8a94a78 Merge branch 'rawhide' into f39