treewide: mark some broken packages as broken

Refs:
e6754980264fe927320d5ff2dbd24ca4fac9a160
1e9cc5b9844ef603fe160e9f671178f96200774f
793a2fe1e8bb886ca2096c5904e1193dc3268b6d
c19cf65261639f749012454932a532aa7c681e4b
f6544d618f30fae0bc4798c4387a8c7c9c047a7c

pkgs/development/python-modules/pytorch/default.nix

@@ -2,7 +2,7 @@
   cudaSupport ? false, cudatoolkit ? null, cudnn ? null,
   fetchFromGitHub, lib, numpy, pyyaml, cffi, typing, cmake, hypothesis, numactl,
   linkFarm, symlinkJoin,
-  utillinux, which }:
+  utillinux, which, isPy3k }:
 
 assert cudnn == null || cudatoolkit != null;
 assert !cudaSupport || cudatoolkit != null;
@@ -27,6 +27,7 @@ let
 in buildPythonPackage rec {
   version = "1.0.0";
   pname = "pytorch";
+  disabled = !isPy3k;
 
   src = fetchFromGitHub {
     owner  = "pytorch";