$ git clone -n https://src.fedoraproject.org/rpms/beust-jcommander.git /var/lib/mock/f41-build-1046667-19094/root/chroot_tmpdir/scmroot/beust-jcommander
Cloning into '/var/lib/mock/f41-build-1046667-19094/root/chroot_tmpdir/scmroot/beust-jcommander'...
$ git fetch origin 5fb2300db4edc6f2f46be6d2a959b8f4cb8a9e9c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/beust-jcommander
 * [new ref]         5fb2300db4edc6f2f46be6d2a959b8f4cb8a9e9c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 5fb2300 Switch to a newer %patch syntax