[Pkg-cmake-team] Bug#809535: cmake: fltk_wrap_ui segmentation fault

[Rob Couto]

I was looking into this for Yoshimi and found that the only
combination is stretch and cmake 3.4.1. This bug does not manifest in
jessie after adding a testing mirror and installing the more recent
cmake, so it seems to not be cmake's own problem.

I tried to compile using 'apt-get source -b' in both jessie and
stretch, and neither would produce a package because 1 of 420
selftests failed, specifically #8 kwsys.testSystemTools. That's the
only clue I got out of it but since it failed in both, I can't say it
is even meaningful.

On stretch, when I went into the Build directory after the tests and
issued a 'make install' to merely try out the locally built copy
without going through the packaging & installing, it produced the same
crash as the official package. The same step repeated on jessie did
not. So it seems to be triggered by stretch's environment and I'm out
of ideas.

The crash itself is by CMake's design-- obviously part of fltk_wrap_ui
is that some lists (filenames etc.) are created but a list is coming
back incomplete or empty, so cmGlobalGenerator::GetGeneratorTarget
prints a message and returns a null pointer which the caller
dereferences unconditionally.

Yoshimi works around this now by using add_custom_command to run
'fluid -c' and adding the output sources to the project in the
ordinary way.

Hope this helps!

-- 
Rob