$ git clone -n https://src.fedoraproject.org/rpms/perl-Test-HexString.git /var/lib/mock/f45-build-26679-618/root/chroot_tmpdir/scmroot/perl-Test-HexString
Cloning into '/var/lib/mock/f45-build-26679-618/root/chroot_tmpdir/scmroot/perl-Test-HexString'...
$ git fetch origin cf94115ecc2e6666b5ce5d1505fb00275e6f8672:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Test-HexString
 * [new ref]         cf94115ecc2e6666b5ce5d1505fb00275e6f8672 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at cf94115 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild