$ git clone -n https://src.fedoraproject.org/rpms/genchemlab.git /var/lib/mock/f41-build-1200016-22410/root/chroot_tmpdir/scmroot/genchemlab
Cloning into '/var/lib/mock/f41-build-1200016-22410/root/chroot_tmpdir/scmroot/genchemlab'...
$ git fetch origin 975d066279d1088994129e8414986c5d69bbfcf7:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/genchemlab
 * [new ref]         975d066279d1088994129e8414986c5d69bbfcf7 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 975d066 Eliminate use of obsolete %patchN syntax (#2283636)