Syncing GCOV env and GCC version to prevent empty uploads

[aminya]

Syncing GCOV env and GCC version to prevent empty uploads

[Spacetown]

I already have a syncVersion function used to sync LLVM tools. We can use the same thing for syncing Gcovr and Gcc

You need to sync gcov (no r at the end) and GCC.

[aminya]

Is this because multiple gcov versions are installed? If that's the case, we should probably set an environment variable in .cpprc when using setup-cpp.

[SK83RJOSH]

Yeah, in my case I had build-essentials (which installs GCC-11) and GCC-12 (via setup-cpp) which lead to empty coverage reports on Ubuntu/macOS. I'd say fixing this in setup-cpp would be the most ideal, though. It's a bit too easy to not notice things are broken, it took me nearly a month. 😅

Somewhat ironically I ran into a GCC bug when using Catch2 as a system library after fixing this in my workflow. The combination of -isystem with sources that have private includes seems to break gcov, which in turn breaks gcovr. Not sure if this should be mentioned in project_options as a potential issue, nor do I know where to raise this issue on the GCC side of things. It's a real nasty one to debug.

[aminya]

Thanks for the explanation. I merged aminya/cpp_vcpkg_project#18 as the temporary fix.
We should implement the permanent fix here in setup-cpp.

setup-cpp/src/gcovr/gcovr.ts

Line 5 in 96bc4cd

return setupPipPack("gcovr", version)

I already have a syncVersion function used to sync LLVM tools. We can use the same thing for syncing Gcovr and Gcc

setup-cpp/src/main.ts

Line 126 in 96bc4cd

if (!syncVersions(opts, ["llvm", "clangtidy", "clangformat"])) {

[aminya]

So, I think we need to add the GCOV environment variable based on the GCC version installed.