$ git clone -n https://src.fedoraproject.org/rpms/perl-Fedora-Rebuild.git /var/lib/mock/f41-build-1153721-21307/root/chroot_tmpdir/scmroot/perl-Fedora-Rebuild
Cloning into '/var/lib/mock/f41-build-1153721-21307/root/chroot_tmpdir/scmroot/perl-Fedora-Rebuild'...
$ git fetch origin 140ab6064ef66faae35d7a38239a2cf79eff7056:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Fedora-Rebuild
 * [new ref]         140ab6064ef66faae35d7a38239a2cf79eff7056 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 140ab60 Eliminate use of obsolete %patchN syntax (#2283636)