$ git clone -n https://src.fedoraproject.org/rpms/golang-modernc-cc-4.git /var/lib/mock/f45-build-12670-443/root/chroot_tmpdir/scmroot/golang-modernc-cc-4
Cloning into '/var/lib/mock/f45-build-12670-443/root/chroot_tmpdir/scmroot/golang-modernc-cc-4'...
$ git fetch origin a39a4d688854d40d8420849d51321e0483f71b94:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/golang-modernc-cc-4
 * [new ref]         a39a4d688854d40d8420849d51321e0483f71b94 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a39a4d6 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild