Except in this case we're literally talking about established CI processes. They're just not triggered by the "C++ contributor" because those don't exist as suc

Except in this case we're literally talking about established CI processes. They're just not triggered by the "C++ contributor" because those don't exist as such. We have GCC contributors, Clang contributors, etc. Periodically a batch of those contributions get marked for testing and they get pushed through various CI processes and bug reports or even PRs get generated. The C++ compiler vendors I am aware of also have access to nontrivial C++ codebases that give them access to these sorts of "see what broke" speculative build jobs: Red Hat has RHEL and CentOS repositories, Microsoft has the presumably massive Microsoft codebases, everyone has access to vcpkg, and so on. I'll also note that this is just normal for sufficiently popular systems languages. If Rust as successful as it seems like it will be, there will some day be far more code outside of public crates than inside them. Anyway, there are some differences for sure, but it's not night and day they way you describe it.