fetchpatch:
# https://github.com/Gecode/gecode/pull/74
(fetchpatch {
  name = "fix-const-weights-clang.patch";
  url = "https://github.com/Gecode/gecode/commit/c810c96b1ce5d3692e93439f76c4fa7d3daf9fbb.patch";
  sha256 = "0270msm22q5g5sqbdh8kmrihlxnnxqrxszk9a49hdxd72736p4fc";
})