$ git clone -n https://src.fedoraproject.org/rpms/perl-Mail-Sender.git /var/lib/mock/f45-build-24624-605/root/chroot_tmpdir/scmroot/perl-Mail-Sender
Cloning into '/var/lib/mock/f45-build-24624-605/root/chroot_tmpdir/scmroot/perl-Mail-Sender'...
$ git fetch origin fdbcf38f8b4d3cadc63ffcd0bebf8a0b97befb1e:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Mail-Sender
 * [new ref]         fdbcf38f8b4d3cadc63ffcd0bebf8a0b97befb1e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at fdbcf38 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild