[Dune] Problems with GMSH reader and ALUGrid

[Christian Engwer]

Hi Andrea,

> I'm trying to build a grid of type ALUGrid starting from a .msh file.
> My computational mesh is made only of tetrahedra, and has Physical entities, since when I wrote that file I needed them.
> 
> Anyway, I can't manage to understand why it doesn't work. This (criptic) error appears on my screen:
> 
> Reading 3d Gmsh grid...
> version 2.2 Gmsh file detected
> terminate called after throwing an instance of 'Dune::IOError'
> Abort trap
> 
> Here there are some short questions:
> 
> 1) could somebody try to compile my .cc file (the .msh file is also attached), to see if it's only a problem on my computer?
> 2) do Physical entities cause troubles in DUNE?
> 3) what does the parameter "insert_boundary_segments = true" mean? Is there any relationship with the coding of the .msh file? Does selecting true or false make any difference in reading from a GMSH file?

before we start checking compiling the code, there is something simple
you can do to help finding the bug.

a) the message you received is a generic message generated by your
   compiler. It states that an exception (please consult your favorite
   C++ manual) has been thrown.
b) you can catch the exception and print the included error message.
   example:
   try {
      do_some_dune_computations();
   }
   catch (Dune::Exception e) {
      std::cout << "ERROR: " << e.what() << std::endl;
   }
c) you can even use your debugger to trace the exception. When using
   gdb, you can start the debugger and then call "catch throw"
   (sometimes you have to run the program once, in order to have all
   symbols available). Now the compiler will stop at that part of your/our
   code, where the exception is thrown.

Hope that helps...

Some general comments. ALUGrid should work with physical entities, it
does for me.

Christian