We've recently had some issues with newer compilers causing issues with builds. See https://github.com/stan-dev/cmdstan/issues/1158 and https://github.com/stan-dev/math/pull/2890 It would be nice to have a monthly run which: - Uses (possibly builds?) the latest of (gcc, clang - Runs the Math unit tests (not expressions, distribution tests) - Builds a bunch of cmdstan models - preferrably at least the example models, the `stanc3/test/integration/good` models.