Re: `message' not outputting the newline "atomically"

[Eli Zaretskii]

> From: Paul Eggert <address@hidden>
> Date: Thu, 20 Jun 2019 10:41:34 -0700
> Cc: address@hidden, address@hidden, address@hidden
> >>
> >> No: POSIX allows stderr to be line-buffered
> > Allows, yes.  But by default it's unbuffered, right?
> 
> No. POSIX allows the default to be line buffered (or to be buffered in 
> other ways, so long as it's not "fully buffered"), and some platforms do 
> that.

But GNU/Linux does start with it unbuffered, or else the code to make
it line-buffered wouldn't be needed, right?

> We really don't want stderr to be unbuffered on GNU/Linux and similar 
> platforms; that would slow down execution signficantly.

I think we do want it to be unbuffered, so that important error
messages are output in their entirety, or as close as possible.  the
main use of stderr is to report errors, not output informative
messages.