$ git clone -n https://src.fedoraproject.org/rpms/rubygem-mini_magick.git /var/lib/mock/f41-build-768805-13481/root/chroot_tmpdir/scmroot/rubygem-mini_magick
Cloning into '/var/lib/mock/f41-build-768805-13481/root/chroot_tmpdir/scmroot/rubygem-mini_magick'...
$ git fetch origin 65ff9962529558bbd7af30a39ea05d28d6bf844a:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-mini_magick
 * [new ref]         65ff9962529558bbd7af30a39ea05d28d6bf844a -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 65ff996 Eliminate use of obsolete %patchN syntax (#2283636)