Re: side note; the vulnerability described in the well-known Ken Thompson paper has been exploited just once in the wild. It's cool, but you could say the same thing about trusting Windows or proprietary drivers or hardware.
Took some digging, but there it is.
Still supports my claim that reproducible builds and Thompson are mainstream buzzwords where our real concern per Orange Book days should be: coding defects in compiler source; effects of optimizations; malicious developers; trusted distribution of source; bootstrapping first, verified, local compiler. That's basically a human and machine verified compiler with simple code and signed zip's. Knocks out Thompson attack as side effect and negates reptoducible build need except for debugging.
Here the attacker just needs to patch a binary once and he already has complete control over the machine, so he has an infinite number of options: from simply manually replacing the binary file before it's uploaded to the website, to replacing gcc with a script that patches the source code before calling the original gcc.