[Zope-CMF] Re: [Zope3-dev] Re: Known working sets II [was: Eggification redux]

2007-09-26 Thread Dieter Maurer
Martijn Faassen wrote at 2007-9-25 19:57 +0200:
> ...
>If you choose for flexibility first, people will need to think about
>versions all the time.

I follow Tres argumentation: somehow the Linux distributors
have this problem mostly solved:

  Standard distributions come with a set of known working components
  and quite weak dependancy declarations.

  When I install additional components, I will be told about
  potential conflicts (based on the weak dependancies) and
  asked what to do (install nevertheless, upgrade more things to
  get dependancies right or abort).

  Usually, I do not have to worry about versions -- only
  occationally (when I see conflict lists) or even more rarely,
  when something breaks even though there has not been a conflict.


We currently made bad experiences with weak dependancies.

I see several reasons for this:

  *  not yet ready distributions (insufficiently tested,
 alpha quality) have been uploaded to PyPI

 We are now aware that we must not do things like this

  *  installation tools have prefered newer versions over
 older ones, even when the newer versions were development/alpha
 while the older ones have been stable

 The tools meanwhile have changed and stick preferably to
 stable versions

  *  The installation tools work incrementally with dependancies
 rather than based on a global dependancy graph.

 This is not yet changed.


Maybe, our bad experience are drastically reduced when the above
reasons are taken care of -- even with weak dependancies?



-- 
Dieter
___
Zope-CMF maillist  -  Zope-CMF@lists.zope.org
http://mail.zope.org/mailman/listinfo/zope-cmf

See http://collector.zope.org/CMF for bug reports and feature requests


[Zope-CMF] Re: [Zope3-dev] Re: Known working sets II [was: Eggification redux]

2007-09-25 Thread Dieter Maurer
Martijn Faassen wrote at 2007-9-25 17:22 +0200:
> ...
>Should we then encourage everyone to hardcode version numbers in their
>setup.py's dependencies list?

I think this goes against building applications from components --
as it drastically increases the probability of conflicts.

Components should are week dependancy requirements to be
maximally usable -- not fixed dependancies.

I think, this holds for frameworks, too, as they are also components.



-- 
Dieter
___
Zope-CMF maillist  -  Zope-CMF@lists.zope.org
http://mail.zope.org/mailman/listinfo/zope-cmf

See http://collector.zope.org/CMF for bug reports and feature requests