Don't override the CC and C++ environment variables

[ninotarantino]

Fixes an issue where some makefiles override the user's CC and C++ environment variables. This can stomp on compiler versions loaded via a package manager like spack or conan.

Closes #1811

[ninotarantino]

@hchen99 This is ready for review.

[ninotarantino]

I'm getting a really bizarre error when building some of the unit tests. Is it alright if we only modify the model directory makefiles and leave the test directory makefiles unchanged from master? This fix is really just to get Trick to build and I'm not too familiar with the test setup here. @hchen99

[hchen99]

I'm getting a really bizarre error when building some of the unit tests. Is it alright if we only modify the model directory makefiles and leave the test directory makefiles unchanged from master? This fix is really just to get Trick to build and I'm not too familiar with the test setup here. @hchen99

It's fine to just modify to get Trick to build.

[ninotarantino]

Sounds good! I pushed an update. I ran the tests locally as well so we should be good now.

[hchen99]

I did checkout your updates and were able to build trick and run all the tests. It seems strange that it can't pass our CI