$ git clone -n https://src.fedoraproject.org/rpms/icecat.git /var/lib/mock/f38-build-side-42-init-devel-1316583-30688/root/chroot_tmpdir/scmroot/icecat
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-1316583-30688/root/chroot_tmpdir/scmroot/icecat'...
$ git fetch origin 239fb07bd41ca2403b0984c037906ef31dfbc053:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/icecat
 * [new ref]         239fb07bd41ca2403b0984c037906ef31dfbc053 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 239fb07 Fix rhbz#2235654