> I honestly don't know how to answer this question. Bootstrapping is an > unrelated problem, and the compiler is not a vital runtime component > of the system, so its dependencies do not need to be exceptionally > robust in the way that glibc's or even libstdc++'s do.
A compiler is a "second order" thing though: its ill behaviour sends ripples through all the stuff it compiles. Suppose that an MPFR upgrade introduces a bug in the library and that the compiler is affected; every single program compiled from now on will be potentially affected by the MPFR bug, even if it has nothing to do with MPFR. I think that the compiler, especially the system compiler, should not depend on dynamic libraries that are lower than it in the system hierarchy, which pretty much leaves only the libc. -- Eric Botcazou