Rust it's worse for that; for full reproducibility you almost need to create a release-centipede from an old GCC-rs (or GCC) compilable release to the current one. At least that's the norm under Guix.

On cproc, cparser, I meant that we have no lightweight c++ compilers and sadly the closest to cparser in lightness it's clang++, because it's either that or the g++ behemoth.