[Catalog-sig] [Distutils] pre-PEP : Synthesis of previous threads, and irc talks + proposals

Tarek Ziadé ziade.tarek at gmail.com
Thu Oct 2 03:10:59 CEST 2008

On Wed, Oct 1, 2008 at 8:28 PM, Phillip J. Eby <pje at telecommunity.com> wrote:
> At 07:55 PM 10/1/2008 +0200, Tarek Ziadé wrote:
>> On Wed, Oct 1, 2008 at 7:29 PM, Phillip J. Eby <pje at telecommunity.com>
>> wrote:
>> > I'm -1 on all of the above.  I think we need a standard for tools
>> > interop
>> > (ala WSGI), not implementation tweaks for the existing tools.  I also
>> > think
>> > that a concrete metadata format proposal is premature at this time;
>> > we've
>> > barely begun to gather -- let alone specify -- our requirements for that
>> > metadata.  (Essentially, only version dependencies have been discussed,
>> > AFAICT.)
>> What are the other important points we need to discuss at this point
>> in your opinion ?
> What information needs to be conveyed by a "build" tool to an "install"
> tool, and vice versa.
> For example, an install tool needs to know what files are documentation,
> which are sample data, and what is part of the library proper, as well as
> what things are scripts (and in what language those scripts are written,
> e.g. Python, shell, batch, etc.).  Some install tools need to know about
> icons, menus, registry info, cron jobs, etc.   (These are perhaps more
> properly the domain of applications than libraries, but I'm going to assume
> that these things are in scope.)
> The way that this information is communicated needs to be extensible, so
> that optional metadata for debs and msi's and rpm's and whathaveyou can be
> incorporated, without needing to modify the standard -- especially if the
> APIs for reading and writing this data are in the stdlib.

So basically with this system, this would mean that an ini-file in my package
would be marked as a configuration file for the installer API, and that third
party tools would decide what to do with this file.

This would mean that my program would have to access to that file
through an API as well to get back to the ini-file in the system.

how would it work ?

> I think I've mentioned all of these previously in the thread.  I also think
> that as a matter of technicalities, these things are not difficult to
> achieve...  but if it they are only achieved *technically*, then the result
> is a failure, not a success.
> In order for the *real* goal to be achieved (i.e., a flourishing
> build/install system for Python), widespread participation and buy-in is
> required.  If the OS people or the big package people (e.g. Zope Corp.,
> Enthought) or the distutils aficionados are left out, then the result won't
> get used.

Well yes, that is basically what we are trying to build since a few
days, but threads are
not linear so people cant' keep up and jump in like that.

So maybe you mentioned that idea before in the thread,
but if we want people to buy the idea, it should be put in the wiki
imho, even prematurely,
and built it there, starting from a small set of points.

I mean, you said earlier that it is premature to write a concrete document
but it's hard to follow in threads the ideas proposed. That was the
idea of my early proposal : start a synthetic list of problems
and for each problem possible solutions. Then discuss them in the ML and
make the right one raise.

That is just my 2 cents on how the discussions go

> I think the best way to ensure that nobody is left out, is to get them to
> participate in the design of a standard that ensures that *they* will be
> able to control their destiny, by creating their own build plugins and/or
> install tools...  or at least having a robust choice of alternatives.
> We need a consensus "de jure" standard (ala WSGI), rather than just an
> ongoing "de facto" standard (ala distutils/setuptools), or we're not making
> any substantial progress, just handing the reins over to somebody else.


>> >> Enforcements:
>> >>    - a binary distribution cannot be uploaded if a source distrbution
>> >> has not been previously provided for the version
>> >
>> > Note that this doesn't allow closed-source packages to be uploaded; thus
>> > it
>> > would need to be a warning, rather than a requirement.
>> >
>> Right. do you agree it is something useful to do ?
> Sure.

Ok so maybe this is *one* problem we can already solve at PyPI with a patch.

>> >>   - PyPI should display the install and test dependencies in the UI
>> >
>> > It could only do this for specific binaries, since dependencies can be
>> > dynamic.
>> >
>> >
>> What dynamic means here ? the python module to static file process or more
>> ?
>> can you provide an example ?
> Dependencies can be platform-specific as well as python-version specific.
>  If you want ctypes, you would depend on it in python 2.4 but not in 2.5.
>  Similarly, if on some platform a certain library is required to implement a
> feature that is natively accessible on other platforms.  In these cases, you
> would have logic in setup.py to detect this and choose the appropriate
> dependencies.

ok, right it is not possible with what we have now.

If each dependency was marked as platform-specific or python-version specific
in the metadata when it is necessary,  we would know them all without calling
extra detection code to build them.

I hate the idea of dynamic metadata in fact. I can't express precisely
why at that point.


Tarek Ziadé | Association AfPy | www.afpy.org
Blog FR | http://programmation-python.org
Blog EN | http://tarekziade.wordpress.com/

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