Re: serial-tests option and backwards compatibility

[Peter Johansson]

On 02/04/2013 11:31 PM, Stefano Lattarini wrote:
> On 02/04/2013 01:16 AM, Luke Mewburn wrote:
[CUT]
> > Especially when the time between previous major releases was 2.5 years.
> >
> > Examining the Changelog and release dates:
> >
> >   2009-12-08  Release automake 1.11.1
> >
> >   2012-02-21  Add "serial-tests" support (in "HEAD")
> >
> >   2012-04-13  Release automake 1.11.5 (without "serial-tests")
> >
> >   2012-05-18  Parallel tests now the default (in "HEAD", not 1.11.x)
> >
> >   2012-06-01  Release automake 1.12.1 (with "serial-tests")
> When I did this, I should really have published a 1.11.x release offering
> this same option as well; that would have removed all confusion.  Sigh,
> such a low-hanging fruit not picked :-(

I disagree. IMVHO micro releases should only fix bugs and not introduce 
new features, i.e., versions within 1.11.x should be both back and 
forward compatible.

The way to avoid these problems would have been to let the fruit sit 
there for, say 3-5 years, and then change the default value.
> >   2013-01-01  Release automake 1.13.1 (parallel tests now default)
> >
> >
> > This isn't the only backwards incompatible change made recently,
> > and in my humble opinion I think the timeframes introducing
> > backwards incompatibility are too aggressive.
> You are not the only one to think so, and I've come to agree (at least
> partially); for some more discussions and background, see:
>
>    <http://lists.gnu.org/archive/html/automake/2013-02/msg00001.html>
>    <http://debbugs.gnu.org/cgi/bugreport.cgi?bug=13578>
>
> So things should proceed more carefully in the future (I hope).

In hindsight, I'm surprised no one objected to your aggressive changes.

> >  From a backwards-compatibility point of view, I think the default
> > should be reverted to serial tests, and make it clearer that
> > parallel tests are available as an option.
> With this I must disagree, sorry.

I agree with your disagreement ;) flip-flopping back and forth would 
cause complete confusion and chaos. It would, however, be useful to 
document a workaround (perhaps in FAQ) how to support serial-test using 
both Automake 1.11 and Automake 1.13. Is there such a workaround?

Cheers,
Peter