$ git clone -n https://src.fedoraproject.org/rpms/git.git /var/lib/mock/f45-build-43632-804/root/chroot_tmpdir/scmroot/git
Cloning into '/var/lib/mock/f45-build-43632-804/root/chroot_tmpdir/scmroot/git'...
$ git fetch origin a40d40b977bd5d619ff8f99c78674383cf09a5d6:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/git
 * [new ref]         a40d40b977bd5d619ff8f99c78674383cf09a5d6 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a40d40b Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild