$ git clone -n https://src.fedoraproject.org/rpms/python-tornado.git /var/lib/mock/f40-build-2682693-67964/root/chroot_tmpdir/scmroot/python-tornado
Cloning into '/var/lib/mock/f40-build-2682693-67964/root/chroot_tmpdir/scmroot/python-tornado'...
$ git fetch origin 7a991f8adf4ae8aa09bcbe13e21542b926be87c3:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/python-tornado
 * [new ref]         7a991f8adf4ae8aa09bcbe13e21542b926be87c3 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 7a991f8 Convert to %autorelease and %autochangelog