$ git clone -n https://src.fedoraproject.org/rpms/python-branca.git /var/lib/mock/f40-build-2266870-54661/root/chroot_tmpdir/scmroot/python-branca
Cloning into '/var/lib/mock/f40-build-2266870-54661/root/chroot_tmpdir/scmroot/python-branca'...
$ git fetch origin 39aa78ef08b328c811423bae46cf2dca2c6466a1:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/python-branca
 * [new ref]         39aa78ef08b328c811423bae46cf2dca2c6466a1 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 39aa78e Update to latest version (#2248173)