$ git clone -n https://src.fedoraproject.org/rpms/perl-BZ-Client.git /var/lib/mock/f45-build-21847-588/root/chroot_tmpdir/scmroot/perl-BZ-Client
Cloning into '/var/lib/mock/f45-build-21847-588/root/chroot_tmpdir/scmroot/perl-BZ-Client'...
$ git fetch origin c229102bb911e2ba942ada1a83b505eecd2d86f1:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-BZ-Client
 * [new ref]         c229102bb911e2ba942ada1a83b505eecd2d86f1 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c229102 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild