[Pythonmac-SIG] Package installation

[Bob Ippolito]

On Apr 18, 2005, at 11:12 AM, konrad.hinsen at laposte.net wrote:

> On Apr 18, 2005, at 15:51, Bob Ippolito wrote:
>
>> 4) Hundreds of hours spent pushing a new format to the rest of the 
>> Python world
>
> The Python world would not care, the packages bundles would be created 
> with some tool based on distutils, just like py2app does today. Only 
> the Mac Python world would be concerned/

Unfortunately it's not that simple because you want to change the way 
the runtime works.

>> 5) Thousands of hours spent modifying existing distutils scripts and 
>> software to deal with it, since it wouldn't be compatible with the 
>> way that things normally work, many packages will need special 
>> treatment.
>
> Good point. How many packages out there do non-standard things in 
> their setup.py that concern the subsequent packaging? I don't know.

Too many.

>> The advantage that bdist_mpkg has is that it's compatible with 
>> anything distutils-based and require no source changes (to either the 
>> setup script or the package itself).  Most of the time, if you click 
>> on a package from http://pythonmac.org/packages/ Safari will unzip it 
>> and open the installer right up... Is it really that hard?
>
> No. The problem I have with it is not installation, but version 
> management. Finding out what versions of what packages are installed 
> is not straightforward. Removing a package requires knowledge that the 
> average Mac user doesn't have. Installing a package that was already 
> installed will happily overwrite files, and might silently downgrade 
> an installation or even create an inconsistent installation.
>
> Of course these problems are the same for other Mac libraries, but at 
> least for Python we could do something about it.

I don't think that Installer will silently downgrade stuff.  Packages 
that create inconsistent installations on upgrade are pretty rare.  
Removing packages is just not something that needs to happen very 
often, and when you actually need to do it, you probably know perfectly 
well how to do it.

>> Can users be trusted to put Python packages in the right place on 
>> their own?  If they have multiple versions of Python installed? I 
>> would say no.
>
> They do manage for applications, so why wouldn't they for Python 
> packages?

Take a look at the archives and see how many people run into problems 
with multiple Python installations, etc.

All that said, if you still think it's worth doing then go write some 
code.  Ideas aren't worth much around here without an implementation.  
It's entirely possible that I'm just jaded from dealing with packaging 
issues the past few years and your proposal is more practical and 
easier than I think it will be.

-bob