[Distutils] upgrading buildout

[Jim Fulton]

On Jul 29, 2008, at 10:39 AM, whit morriss wrote:

> whit morriss wrote:
>> I'm perhaps running buildout in a bit of unusual fashion (from my  
>> virtual env bin rather than the builds bin) and updated it recently  
>> from 1.0.2 to 1.1.0 to debug some issue folks were having with  
>> fresh checkouts of one of my builds (see previous message).
>
> as a caveat for others, we also noticed a number of older recipes  
> which are cached don't take the new allowed hosts arg.  It looks  
> like older copies (in this case zc.recipe.egg) got installed in the  
> virtualenv sitepackages (probably for the purposes of investigation)  
> or egg caches and did not get updated.

This sounds like a bug. I expect buildout to get and use the newest  
distributions that satisfy its requirements regardless of whether  
older versions are in site-packages. One way that this would fail is  
if eggs are installed into site-packages as develop eggs, aka "single- 
version-externally-managed".  buildout gives preference to develop  
eggs even if there are newer non-develop eggs. Distributions installed  
using -single-version-externally-managed are tagged by setuptools as  
develop eggs.  I really wish setuptools made a distinction between  
single-version-externally-managed and develop eggs.

Was the zc.recipe.egg distribution installed into your site- packages  
using -single-version-externally-managed? (This will be the case if  
the egg contents are stored directly in site-packages rather than  
having egg files or directories.)

> In systems like buildout where every buildout is necessarily a patch  
> work of called dependencies (most frameworks or component systems  
> are like this in one way or another, sometimes referred as what  
> separates frameworks from libs), it would be useful to have some  
> mechanism for propagate an update of a downstream component.

By "downstream", do you mean a dependency?

>  Does setuptool support anything like this (I'm doubting it?)?   
> could or does zc.buildout?
>
> for builds, I could see this being handled more as a migration.   
> Update the framework library, run a migration to upgrade all the  
> component libraries, rebuild.

As a general rule, buildout always tries to find the latest versions  
of all distributions used, including dependencies.  One exception to  
this is that it prefers develop eggs.

Jim

--
Jim Fulton
Zope Corporation