[Distutils] Better version pinning in buildout (buildout-versions)
aclark at aclark.net
Mon Jan 7 01:38:40 CET 2013
On 2013-01-05 22:47:05 +0000, Jim Fulton said:
> Lots of people agree that buildout-versions us useful
> and the author has volunteered to contribute it to core buildout.
> Of course, as a part of buildout, rather than an extension, it can be
> streamlined a bit. Also, based on experience, I think we can simplify
> versions management a bit further.
> When I implemented the versions mechanism in buildout, I decided to
> build on the configuration model. This has worked pretty well,
> especially for complex use cases like layering version specifications
> (e.g. building on "known good sets"), but this approach has added a
> little bit of drudgery. Because I didn't want to stomp on existing
> versions sections, I made the name of the section containing versions
> require configuration, which means you end up with::
> versions = versions
This is confusing… but I was thinking more along the lines of adding a
default setting "versions = versions", at which point end users need
only to add a section named [versions].
> I also think it's a little awkward to have buildout update files that
> are also edited by users.
> Based on this, I propose that buildout-versions get incorporated into
> buildout in the following way:
> 1. New buildout option named ``versions-file`` which takes the name of
> a file. to contain version information. It is not a configuration
> file. It is a file consisting of comments (#...) and version
> # whatever
> foo = 1.3
> If it doesn't exist, it wil be created. (I'm not sure it's a good
> idea to create the file implicitly though.) Any version constraints
> found in the file are added to the buildout version constraints.
> Version constraints found in the versions-file override version
> constraints obtained via a versions option, if any.
+0 And if you do this, it may cause confusion with folks familar with
the current practice. Is it possible to support both? (At the very
least, I'd make Buildout always use versions specified inside a
[versions] section i.e. by making "versions = versions" the default.)
> 2. New buildout option: ``update-versions-file``. If this is true,
> then any picked/unpinned versions are appended to the versions file
> and reported in the output. There's a command-line option, ``-V``
> to set this to true for a run. It's an error to use this if
> ``versions-file`` isn't set.
So this helps encourage folks to pin versions by auto-generating the
versions file and using it on subsequent runs? To give some real world
context, IIUC I can create a buildout:
update-versions-file = true
parts = zope2
recipe = zc.recipe.egg
If I run this, I'll get a versions.txt file with ZTK packages in it
(but not necessarily the packages required to run Zope2, since Zope2
itself does not know about its own KGS i.e.
subsequently PyPI will return the latest version of each
> 3. The ``allow-picked-versions`` option gets a new allowed value of
> ``warn``. if there are unpicked versions and this option is set to
> ``warn``, then picked/unpinned versions are reported. Also, if
> ``allow-picked-versions`` is true, there will be no error if
> ``update-versions-file`` is true.
> 4. New buildout option: ``python-version`` that restricts the Python
> version, with the same semantics as buildout-version provides now.
Meaning I can't bootstrap a Plone 4 buildout with Python 2.4 nor a
Plone 3 buildout with Python 2.7? If so, +1.
> Thoughts? Did I miss anything?
Alex Clark · https://www.gittip.com/aclark4life/
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