[CMake] Internal error bug in v3.4.2.

[Brad King]

On 01/19/2016 08:42 PM, Gonzalo wrote:
> I compiled v3.4.2 and after installing it in /usr/local, I tried running 
> it in a project that was working fine with cmake 2.8.

Thanks for reporting this.  The 2.8 series was quite long.  To help narrow
the changes between these versions, what 2.8 version were you using?

> CMake Internal Error (please report a bug):
>    Missing cmGeneratorTarget instance!
[snip]
> 0x5aa51d : cmTarget::GetSourceFiles(std::vector<cmSourceFile*, std::allocator<cmSourceFile*> >&, std::string const&) const [(cmake) ???:-1]
> 0x697281 : cmFLTKWrapUICommand::FinalPass() [(cmake) ???:-1]
> 0x54b9bd : cmMakefile::FinalPass() [(cmake) ???:-1]
> 0x54babd : cmMakefile::ConfigureFinalPass() [(cmake) ???:-1]

This looks like the FLTK_WRAP_UI() command is not working for you.
The command is a holdover from very early CMake days when we did not
have modern add_custom_command and macro/function capabilities.
AFAIK it is not widely used and has only minimal coverage in CMake's
test suite.

I cloned mrViewer but it has way too many dependencies for me to try
to configure a full build locally.  I stripped down the

  mrViewer/src/CMakeLists.txt

enough to get it to configure and call FLTK_WRAP_UI but I'm unable to
reproduce this problem.

Please try stripping the CMake files in mrViewer down a bit at a time
until the problem goes away and then try to use that to produce a
small example demonstrating the problem.

Thanks,
-Brad