$ git clone -n https://src.fedoraproject.org/rpms/perl-Boulder.git /var/lib/mock/f45-build-21896-588/root/chroot_tmpdir/scmroot/perl-Boulder
Cloning into '/var/lib/mock/f45-build-21896-588/root/chroot_tmpdir/scmroot/perl-Boulder'...
$ git fetch origin a01d57329f12bc547a83faad19cf8cf6492dc362:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Boulder
 * [new ref]         a01d57329f12bc547a83faad19cf8cf6492dc362 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a01d573 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild