$ git clone -n https://src.fedoraproject.org/rpms/R-qtl.git /var/lib/mock/f39-build-1923462-43006/root/chroot_tmpdir/scmroot/R-qtl
Cloning into '/var/lib/mock/f39-build-1923462-43006/root/chroot_tmpdir/scmroot/R-qtl'...
$ git fetch origin 6154381166a0caacdff4f4eea6dd8425d4a32da8:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-qtl
 * [new ref]         6154381166a0caacdff4f4eea6dd8425d4a32da8 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6154381 Update to 1.62