__caddr_t was rejected by the POSIX standard.

[atupone]

https://github.com/facebookincubator/gloo/blob/e6d509b527712a143996f2f59a10480efa804f8b/gloo/common/linux.cc#L201

I think it can be subs with void *

[stemann]

Might be fixed by #339, as it replaces __caddr_t with caddr_t.