MATLAB: Mex ‘include’ path merged with working directory path

include pathmex compiler

I am attempting to compile a mex function. For some reason, the 'include' path I specify gets merged into my current working directory path. I don't recall seeing this before, although I spend most of my time in Linux and am working short-term on a Windows machine.
Below is the error message I get. Note that the line that is cited in error has the correct path but it is somehow interpreted to the wrong path.
Error using mex
C:\Users\john.anderson\Documents\MATLAB_Toolboxes\KWtools\TestPost\Matlab_mexa64\source\Files\Altair\2017\hm\include\ not found;
check that you are in the correct current folder, and check the spelling of
'C:\Users\john.anderson\Documents\MATLAB_Toolboxes\KWtools\TestPost\Matlab_mexa64\source\Files\Altair\2017\hm\include\'.
Error in makemex64 (line 30)
mex -v CC=g++ -O -DSNPRINTF=snprintf -IC:\Program Files\Altair\2017\hm\include\ ./RunHyper.c …

Best Answer

 mex -v CC=g++ -O -DSNPRINTF=snprintf -IC:\Program Files\Altair\2017\hm\include\        ./RunHyper.c ...
means
mex ...
    -v ...
    CC=g++ ...
    -O ...
    -DSNPRINTF=snprintf ...
    -IC:\Program ...
    Files\Altair\2017\hm\include\ ...
    ./RunHyper.c ...
where each of those is a separate input argument.
The space in the directory name is confusing it.
You should be using
-I"C:\Program Files\Altair\2017\hm\include\"
but since some of that part is automatically generated, it sometimes is not worth fighting it to force it to generate quotes at the proper places. Much of the time it turns out to be easier to move include directories and libraries to paths that do not include spaces (or non-ANSII characters for that matter.)
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