@apaszke
I think it seems that the biggest difference that I could understand to make a difference between the ubuntu system the code works fine on and the arch system where it hangs is that the arch version is running off glibc 2.25 and the ubuntu version is running off of glibc 2.23, each with their respective versions of libpthread.
I realize now that conda doesn’t pack its own version of glibc really, and I’m not sure how one would test building pytorch against different versions of glibc on the same system.
If this is the case (which it’s too soon to say), anyone running a version of glibc >=2.25 is going to have problems running pytorch.