[Dune] Signal: Segmentation fault in a 3D mesh generator

[Christian Engwer]

Dear Jonas,

>    [jonas-MacBookPro:00477] *** End of error message ***
>    Segmentation fault (core dumped)/

a segmentation fault means that your program is accessing a memory
address it is not allowed to access.

While it might be, that this is due to an internal bug in DUNE, it is
more probable that there is a bug in your program.

Typical reasons are

 - a dangling pointer, i.e. you have kept a raw pointer that points to
   an object that is already freed.
 
 - stack corruption, e.g. due to out-of-bounds access you can modify
   data accidentally. Such a change can then modify a pointer, which
   is now invalid.

The first step to reproduce should be to compile with debugging
symbols (e.g. 'g++ -g') and us a debugger (e.g. 'gdb') to check for
the place where the error occurs. Perhaps this already reveals the
problem. As segfaults an easily be caused by a programming error might
be in a totally different spot (see my note on stack corruption). If
this is the case a memory checker might help that add additional
bounds checks.

If it turns out to be related to internals of DUNE, please open a bug
report in gitlab and provide a minimal test case.

Thanks!
Christian