Glibc support policy?

I tried and failed to find what’s the lower bound for glibc currently required by LLVM (or its subprojects). Neither on google, on GH code search, nor in discourse.

It’s relevant to me because it determines whether a something is a bug (unguarded reliance on a symbol not available before glibc 2.16 in compiler-rt) or just out-of-support.

I wanted to ask here before filing a bug directly (maybe the answer is obvious and I missed it), but I do think it could be documented more prominently… :upside_down_face:

I don’t think we have a formal policy here. LLVM doesn’t normally require very much from the C library, so it comes up rarely.

Informally, we support whatever the buildbots test. So the baseline is probably RHEL 7, i.e. glibc 2.17. But we can probably stretch back a bit further than that if the required changes are minor.