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

[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