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.
Cool!
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
[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.
+0
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
specifications::
# 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:
[buildout]
update-versions-file = true
parts = zope2
[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.
http://download.zope.org/Zope2/index/2.13.19/versions.cfg. And
subsequently PyPI will return the latest version of each
install_requires value.)
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.
+0
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?
Jim
--
Alex Clark · https://www.gittip.com/aclark4life/
_______________________________________________
Distutils-SIG maillist - Distutils-SIG@python.org
http://mail.python.org/mailman/listinfo/distutils-sig
