$ git clone -n https://src.fedoraproject.org/rpms/perl-PAR-Packer.git /var/lib/mock/f42-build-side-1-3499855-45966/root/chroot_tmpdir/scmroot/perl-PAR-Packer
Cloning into '/var/lib/mock/f42-build-side-1-3499855-45966/root/chroot_tmpdir/scmroot/perl-PAR-Packer'...
$ git fetch origin b4bcd8bcb3ef4f82579ca518211857c1b07894ff:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-PAR-Packer
 * [new ref]         b4bcd8bcb3ef4f82579ca518211857c1b07894ff -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b4bcd8b Rebuild for Perl 5.40.2