On Apr 2, 2008, at 3:44 PM, Hanno Schlichting wrote:

Hi.

I ran into a problem with zc.buildout while upgrading a customers buildout and wondered if the problem I encountered is a general one.

The buildout in question had one recipe pinned down to an exact version as in:

[buildout] parts = plone

[plone] recipe = plone.recipe.plone==3.0.2

To upgrade this environment I changed the explicit version to 3.0.6:

[buildout] parts = plone

[plone] recipe = plone.recipe.plone==3.0.6

When rerunning the buildout script I got an error during uninstall of the plone part. It complained that the plone.recipe.plone recipe version 3.0.2 was not available.

From my understanding of this, buildout parses the version requirements first and at the point where it wants to uninstall the plone part, only the newer 3.0.6 version of the recipe is available.

The workaround was to change .installed.cfg and remove the version restriction, so any version of the recipe would be accepted to uninstall the part, but I wonder if there is a general problem here or if we are misusing the version restrictions?

I think there is a general problem and no, you aren't miss-using the the version restriction.

I have the feeling that buildout should either add the old recipe to the environment to satisfy the uninstall requirement

Unfortunately, there can be only one version in the environment at a time.

or accept newer versions of a recipe to uninstall older versions.

That is probably better. Another option might be to uninstall in a separate process. (Just thinking out loud.)

Thoughts?

I need to think about this. :) I haven't seen this situation before, although I should have expected it. I'll think about this and respond in a day or 2. If I forget, bug me, or create a launchpad issue. Jim -- Jim Fulton Zope Corporation