Comment 6 for bug 1745075

static void FDWrite(int fd, const char* buf, size_t len) {
  while (len > 0) {
    ssize_t r;
    NO_INTR(r = write(fd, buf, len));
    RAW_CHECK(r >= 0, "write failed");
    buf += r;
    len -= r;
  }
}

RAW_CHECK failed.