should this be "command":"clang++"... with clang++ on the PATH?
This should check a diagnostic rather than rely on the error code, I think
Both the relative and the absolute path should work, but cmake produces absolute paths. Hence the test.
Done. We rely on the absence of a diagnostic (the unresolved error for vector), error-code seemed like a simpler way to do this.
Is there a test for the other case? (In the clang repo rather than here is fine)
I think emitting a diagnostic would make this a much more robust test, but up to you.
No, will add one in the clang repo.
should this be "command":"clang++"... with clang++ on the PATH?