ref: d935bb25d2b7ae1f5fa67496eac9da40c2e7dbd4
parent: eb73718c25eede77fa970c837f6c000d84ca8f55
author: Ori Bernstein <ori@eigenstate.org>
date: Fri May 1 09:29:08 EDT 2020
use #error when missing define This makes it easier to figure out what's going wrong when we forget to define _POSIX_SOURCE.