Op 05-01-13 23:47, Jim Fulton schreef:
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]
...
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
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.
A section header should be permitted too, specifically '[versions]', so
it is just a normal buildout file.
Would this file be implicitly added at the end of the 'extends' list?
Or would the user still need to do that explicitly.
I always just let buildout-versions or buildout.dumppickedversions print
the picked versions and when I agree I paste them in versions.cfg or
another buildout file.
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.
+0. I would probably not use this bit, but some people do use it in the
current extensions.
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.
+1. In a development setup I would probably set this to 'warn' and in
production to 'false'.
Say there is a buildout config with one or more versions that are not
pinned. What would the effect be of the various options? Here is a
truth table:
allow-p-v update-v-f result
false false buildout quits with error
false true buildout quits with error
warn false buildout reports versions on stdout
warn true buildout edits versions file
true false buildout reports versions on stdout
true true buildout edits versions file
From that, I wonder if there is a practical difference between
allow-picked-versions being set to 'warn' or 'true'. Perhaps when it is
true and update-versions-file=false (row 5), you do not want to print
anything?
4. New buildout option: ``python-version`` that restricts the Python
version, with the same semantics as buildout-version provides now.
+1
--
Maurits van Rees: http://maurits.vanrees.org/
Zest Software: http://zestsoftware.nl
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