$ git clone -n https://src.fedoraproject.org/rpms/charliecloud.git /var/lib/mock/f40-build-792912-138676/root/chroot_tmpdir/scmroot/charliecloud
Cloning into '/var/lib/mock/f40-build-792912-138676/root/chroot_tmpdir/scmroot/charliecloud'...
$ git fetch origin c50d393c4f80599586dee398aece27c2c13346b0:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/charliecloud
 * [new ref]         c50d393c4f80599586dee398aece27c2c13346b0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c50d393 fix gitignore; add patch