[Pythonmac-SIG] Package installation

[Bob Ippolito]

On Apr 18, 2005, at 12:01 PM, konrad.hinsen at laposte.net wrote:

> On 18.04.2005, at 17:43, Bob Ippolito wrote:
>
>> Unfortunately it's not that simple because you want to change the way 
>> the runtime works.
>
> But only by adding a strategy for searching for packages. Those who 
> don't use it will never find out.

That doesn't work for scripts, headers, dependent libraries, etc.  
distutils has to know how to find the headers, users have to know how 
to find the scripts so they can put them in their PATH, dependent 
libraries have to go somewhere (i.e. wxPython -> wxWidgets, pygame -> 
SDL, SDL_*), etc.

>> I don't think that Installer will silently downgrade stuff.  Packages 
>> that create
>
> Does it keep track of version numbers then? The Apple docs are quite 
> silent about the installer.

Apple has plenty of docs on the installer, the format it uses, what 
happens during an installation, etc.  Yes, the version number is in the 
receipt.

>>  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.
>
> Removing is indeed frequent only as a step in updating. There are 
> cases where an update requires removing the old version first, e.g. 
> when a module has been replaced by a subpackage of the same name.

Yes, there are cases where that happens, but they're rare.  It's both 
possible and reasonable to do this from a preflight upgrade script in 
an installer package for those special cases.

>> Take a look at the archives and see how many people run into problems 
>> with multiple Python installations, etc.
>
> Isn't that mostly because of MacPython and Fink Python being installed 
> in parallel? Fink Python wouldn't be concerned at all.

No, not really.  Search the archives.

-bob