Versions coming from system packages aren't picked up

[flacoste]

Using buildout 1.5.2, when site-packages are allowed, I've noticed that buildout-versions doesn't pick up any of the dependencies found in site-packages.

[cjw296]

What happens if you specify a version and that version comes from site-packages?
Does it work as expected?

[flacoste]

Yes, that works.

An example will probably make this clearer.

If I have in my biuldout.cfg:

extensions = buildout-versions
buildout_versions_file = versions.cfg
versions = versions
extends = versions.cfg
include-site-packages = true
allowed-eggs-from-site-packages =
psycopg2

eggs =
psycopg2

When I run buildout, I would expect psycopg2 to be added to versions.cfg with the versions number used by the system psycopg2 package, but buildout-versions doesn't report about it, nor add it to the file.

[cjw296]

Okay, can you turn the above into a complete buildout.cfg that I can test with?

[flacoste]

Sure:

[buildout]
parts =
issue5
extensions = buildout-versions
buildout_versions_file = versions.cfg
versions = versions
extends = versions.cfg

include-site-packages = true
allowed-eggs-from-site-packages =
psycopg2

prefer-final = true
allow-picked-versions = false

[issue5]
recipe = zc.recipe.egg
eggs =
psycopg2

When I run this I'll get the following (beginning ommited):

Updating issue5.
Installing 'psycopg2'.
We have the best distribution that satisfies 'psycopg2'.
Egg from site-packages: psycopg2 2.4.4
Versions had to be automatically picked.
The following part definition lists the versions picked:
[versions]
buildout-versions = 1.7
distribute = 0.6.24
zc.buildout = 1.5.2
zc.recipe.egg = 1.3.2
This information has been written to 'versions.cfg'

I'd have expected a psycopg2 = 2.4.4 in there.