On Sun, 7 Jul 2019 at 15:52, Eli Zaretskii <eliz@gnu.org> wrote:

> > Cc: larsi@gnus.org, daniele@grinta.net, emacs-devel@gnu.org
> > From: Paul Eggert <eggert@cs.ucla.edu>
> > Date: Sat, 6 Jul 2019 18:16:03 -0700
>


> As for "make -O", could it be that you were talking literally about
> that, i.e. about "make -O=target"?  Because I meant "make -O=line",
> which AFAIR slows down the build only slightly, and provides the
> line-level separation that you want to see.  I think using that is a
> good compromise.
>

"make -O=line" buffers all output from one line of the Makefile.
For typical targets with only one command, it's the same as "-O".