hpatch was written without symmetry in mind, so they are very likely incompatible. Hpatch works by using its own InteractionGraph in packing, and generally symmetry also requires its own InteractionGraph in packing, so to get both I think someone would have to write an IG to handle both at the same time (which apparently hasn’t been done). I’ve emailed the Hpatch author to see if he knows any workarounds.
I’ve never tested the hpatch score with symmetry enabled, but I feel like there’s no reason it can’t work. As Steven said, it may require creating a new InteractionGraph type, something like a SymmLinearMemoryHPatchInteractionGraph in the InteractionGraphFactory.cc file. The InteractionGraph classes are templated, so it should be possible to create a SymmLinMemIG which has an HPatchIG within it (“under the hood”). If you send me your input file and a command line, I can look into this some more.