roystgnr

Let's not merge this until we're certain it's what you need on the MOOSE side of things too (which I haven't looked at yet), but the libMesh additions seem quite...

Skimming your MOOSE branch, I admit I see *more* code than I like, which makes me wonder if this definitely is the best solution ... but I can't say I...

> I'd guess there's some C++ rule about enum classes getting default initialized to their lowest entry and so this will work fine as-is, Or maybe I couldn't find such...

> If I should add some test files into the libmesh repo that call these functions, in order to improve coverage, let me know. That would definitely be a good...

If you've got a solid POSIX environment set up; it's still just `configure; make`. It's been a very long time since I've done that (with Cygwin; I haven't even tried...

So not only is the new PetscDiffSolver option not working, the old functionality has regressed. Didn't even think to check for that by hand...

I ran across #1902 again today, and I'm wondering if I can kill two birds with one stone here. A flood algorithm that fills an unordered_set (or maybe an id-indexed...

Could you double-check your libmesh_config.h and make sure LIBMESH_TRILINOS_HAVE_DTK is defined? Although honestly I don't see how this exact error could happen. If that macro wasn't defined it should have...

Try running (with c++filt installed) ``` nm src/solution_transfer/.libs/libmesh_opt_la-dtk_solution_transfer.o | c++filt | grep '~' | grep -v std ``` and see if it shows the ~DTKSolutionTransfer destructor? If that works try...

(both from the top of your build directory)