Re: [bug #33138] .PARLLELSYNC enhancement with patch

[Paul Smith]

On Sun, 2013-04-28 at 20:00 +0300, Eli Zaretskii wrote:
> > I've pushed a change to add a new argument to the -O/--output-sync
> > option, "job", to write output after each line of the recipe.
> 
> What is its purpose?  To avoid mixing in the same screen line
> characters from several parallel sub-makes?  (That does happen, albeit
> rarely.)  Or is it something else?

I'm not sure exactly what you mean by your second sentence.  However I
asked the same question you did about this feature.

Frank had a use-case: he was tracking which jobs were active/still
running by making all his recipes look like this:

  target:
          @echo start: $@
          ... recipe ...
          @echo end: $@

This allows a higher-level, dynamic interface to track which jobs are
running, when they started, etc. and track the build.

Although I implemented this because it was simple, I'm not so sure this
is a real use-case.  Or to be more accurate, I agree that it's a real
use-case but I don't think this is a good solution to the problem.

I suspect that a better solution might be to create a "machine
interface" mode for make, as some other GNU CLI tools like GDB, etc.
have.  This interface would be well-defined and unchanging and easily
machine-parseable, and allow people to write front-ends to more
accurately examine make's output.

However, for now this new output-sync mode doesn't seem to be harmful.