$ git clone -n https://src.fedoraproject.org/rpms/ImageMagick.git /var/lib/mock/f40-build-775522-128090/root/chroot_tmpdir/scmroot/ImageMagick
Cloning into '/var/lib/mock/f40-build-775522-128090/root/chroot_tmpdir/scmroot/ImageMagick'...
$ git fetch origin aae782fe0aab975be169d549d928910fe58e1db2:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ImageMagick
 * [new ref]         aae782fe0aab975be169d549d928910fe58e1db2 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at aae782f fix PKG_CONFIG_LIBDIR