$ git clone -n https://src.fedoraproject.org/rpms/pgbouncer.git /var/lib/mock/f42-build-side-1-3569516-46747/root/chroot_tmpdir/scmroot/pgbouncer
Cloning into '/var/lib/mock/f42-build-side-1-3569516-46747/root/chroot_tmpdir/scmroot/pgbouncer'...
$ git fetch origin d271bcbbcd05b2a73c0999599df2a903e356027e:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/pgbouncer
 * [new ref]         d271bcbbcd05b2a73c0999599df2a903e356027e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at d271bcb Fix logrotate (#2364112).