$ git clone -n https://src.fedoraproject.org/rpms/perl-Data-MessagePack.git /var/lib/mock/f45-build-22884-594/root/chroot_tmpdir/scmroot/perl-Data-MessagePack
Cloning into '/var/lib/mock/f45-build-22884-594/root/chroot_tmpdir/scmroot/perl-Data-MessagePack'...
$ git fetch origin f704da4040bf18cf78341fbaf2c2e1e78f03071e:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Data-MessagePack
 * [new ref]         f704da4040bf18cf78341fbaf2c2e1e78f03071e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f704da4 Perl 5.44 rebuild