Default output-sync setting (was: Re: [bug #33138] .PARLLELSYNC enhancement with patch)

[Paul Smith]

Now that we seem to have a workable solution for output synchronization
for both POSIX and Windows systems, I wonder if we shouldn't consider
enabling it as the default mode when parallel builds are running.

I understand that this will be a change that could be visible (beyond
the collection of output) due to using a temp file instead of a
terminal.  Of course people can still use -Onone if they want old
behavior.

However assuming the new mode works and is reliable, and is not a
performance bottleneck, I'm hard-pressed to see why a well-ordered
output would not be preferable to just about everyone, and hence
shouldn't be the default.

Of course it's possible that writing to a file, rather than spewing to
stdout, WOULD be noticeably performance impacting at least in some
situations/systems.


Comments?