$ git clone -n https://src.fedoraproject.org/rpms/python-astropy.git /var/lib/mock/f40-build-2406758-60558/root/chroot_tmpdir/scmroot/python-astropy
Cloning into '/var/lib/mock/f40-build-2406758-60558/root/chroot_tmpdir/scmroot/python-astropy'...
$ git fetch origin e46575dca41dd2dd38677cabf9149f3138177a8e:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/python-astropy
 * [new ref]         e46575dca41dd2dd38677cabf9149f3138177a8e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at e46575d Add patch to fix FTBS