Getting codegen to work in MATLAB

[makeller1]

After troubleshooting getting codegen to work in MATLAB, I've got some errors to report and solutions for people struggling like I was. If these cannot be fixed, it would be helpful to have some messages in the docs about these specifics.

• In MATLAB 2021a the supported minGW compiler (installed in the MATLAB gui as a support package) fails with error "Error configuring CMAKE environment" because "CMAKE_MAKE_PROGRAM" is not set. The osqp docs currently suggest installing this compiler through a url to matlab's supported compilers, so this error is bound to happen for others.

Solution:

1. Install the minGW compiler from TDM-GCC at https://jmeubank.github.io/tdm-gcc/download/
2. Add this line to your matlab code:
   setenv('MW_MINGW64_LOC', 'C:\TDM-GCC-64');
3. Add this line to your matlab code:
   setenv('PATH', [getenv('PATH') ';C:\TDM-GCC-64\bin']);
   where C:\TDM-GCC-64 is replaced in 2 and 3 with the location of your TDM-GCC installation.

• When installing osqp from the MATLAB terminal using the commands given in the osqp docs:
  >>websave('install_osqp.m', 'https://dl.bintray.com/bstellato/generic/OSQP/0.6.2/install_osqp.m');
>>install_osqp
  the installation is saved to whatever directory is matlab's current working directory. If this path is too long, codegen will fail at some point due to mex.

Solution:

1. Delete the osqp folder.
2. Set matlab's working directory to a short path.
3. Reinstall osqp using the same commands as before.