$ git clone -n https://src.fedoraproject.org/rpms/perl-Devel-Dumpvar.git /var/lib/mock/f45-build-23079-595/root/chroot_tmpdir/scmroot/perl-Devel-Dumpvar
Cloning into '/var/lib/mock/f45-build-23079-595/root/chroot_tmpdir/scmroot/perl-Devel-Dumpvar'...
$ git fetch origin 2e7783fea76c8896284d526f6ac511f185b4e8a5:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Devel-Dumpvar
 * [new ref]         2e7783fea76c8896284d526f6ac511f185b4e8a5 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 2e7783f Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild