$ git clone -n https://src.fedoraproject.org/rpms/rubygem-optimist.git /var/lib/mock/f40-build-2224198-52771/root/chroot_tmpdir/scmroot/rubygem-optimist
Cloning into '/var/lib/mock/f40-build-2224198-52771/root/chroot_tmpdir/scmroot/rubygem-optimist'...
$ git fetch origin bb913b40b2256bd885b1e2af583a4512c268d2a8:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-optimist
 * [new ref]         bb913b40b2256bd885b1e2af583a4512c268d2a8 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at bb913b4 Apply the upstream PR to support minitest 5.19+