$ git clone -n https://src.fedoraproject.org/rpms/perl-Gtk2.git /var/lib/mock/f41-build-816691-150352/root/chroot_tmpdir/scmroot/perl-Gtk2
Cloning into '/var/lib/mock/f41-build-816691-150352/root/chroot_tmpdir/scmroot/perl-Gtk2'...
$ git fetch origin 76a5e2e6e4c7e7e1e10d00f06c8e7ee8d48e09c1:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Gtk2
 * [new ref]         76a5e2e6e4c7e7e1e10d00f06c8e7ee8d48e09c1 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 76a5e2e Perl 5.40 rebuild