Control: reassign -1 src:simgear Control: tags -1 fixed-upstream patch
The function it complains about is indeed broken, but is currently unused, so shouldn't be causing any problems other than this FTBFS.
Fixed by http://sourceforge.net/p/flightgear/simgear/ci/a6290e367a461b9b083fd2331ccf8f9edf624e69/