lines 258-306 of file: setup.py

{xrst_begin setup.py.error}
{xrst_spell
   cholmod
   cxx
   homebrew
   suitesparse
   var
   wno
}

setup.py Error Messages
#######################

cholmod.h
*********
This message can only occur when
:ref:`install_settings.py@include_mixed` is true.

Message
=======

| |tab| ... fatal error: 'cholmod.h' file not found
| |tab| # include <cholmod.h>

Solution
========
If you get this message, find out where ``cholmod.h`` is on your system.
For example, if you are using homebrew on the Mac, the following command
will find cholmod.h::

   find -L $HOMEBREW_PREFIX -name 'cholmod.h'

On one system, the result of this command was::

   /opt/homebrew/include/cholmod.h
   /opt/homebrew/var/homebrew/linked/suite-sparse/include/cholmod.h
   /opt/homebrew/opt/suite-sparse/include/cholmod.h
   /opt/homebrew/opt/suitesparse/include/cholmod.h
   /opt/homebrew/Cellar/suite-sparse/7.1.0/include/cholmod.h

So cholmod was installed in the /opt/homebrew/include directory.
Changing :ref:`install_settings.py@extra_cxx_flags` as follows
solved the problem::

   extra_cxx_flags  = '-Wall -pedantic-errors -Wno-unused-result -std=c++11'
   extra_cxx_flags += ' ' + '-I /opt/homebrew/include'


{xrst_end setup.py.error}