[Pythonmac-SIG] portability problem with py2app-built app

[has]

Bob wrote:

>>Having a problem with a semi-standalone app built using py2app 
>>0.1.7. Building it OMM (OS10.2.8, MacPython 2.3.3) and the app 
>>works fine here, but on the user's machine (OS10.3, standard 
>>Apple-installed MacPython) it shows a dialog saying that it 
>>requires Python 2.3. What's wrong?
>>
>Nothing.  The semi-standalone option depends on an equivalent Python 
>installation and it didn't find one. An equivalent Python 
>installation means that there is either one in the bundle, or on the 
>filesystem in an identical location.

Ahh, right. This wasn't obvious.


>When using --semi-standalone, your Python extensions can't have 
>their Mach-O headers rewritten. If they are linked on a version of 
>Python or platform that doesn't use -undefined dynamic_lookup,

You mean installations like (e.g.) Apple's MacPython on 10.3? Sorry 
my C/ObjC is extremely limited - probably best if it's explained in 
dummy talk. Is there a definitive document I can go read that 
describes the scope, scale and implications of this problem?


>You can override the contents of PyRuntimeLocations with the plist 
>option, but the recommended solution to building a Python 
>application that runs on multiple versions of OS X is to use a 
>standalone bundle built on[1] the earliest supported version of Mac 
>OS X.

Only problem with that is it bumps each app's size by about 7MB, 
which is a bit of a hog for any user on dialup... especially if I'm 
shifting serveral 'small' apps at a time.


>In the future, py2app may audit your application to determine if it 
>is safe to use "any" version of Python (no extensions, or extensions 
>with only -undefined dynamic_lookup).. however, that still won't 
>support your use case.

My immediate problem is making ASTS portable, but I've got other apps 
in development that are going to have the same problem. And I can't 
afford a copy of 10.3 to do a parallel build on, so building 
cross-platform on 10.2 is currently my only option. What if I exclude 
appscript from the app (it can be provided as a separate one-off 
installation via a third-party binary installer) and munge its 
Info.plist to pick up Apple's MacPython?


>In theory, it could use macholib to rewrite the headers at runtime 
>into a temp dir if it determines that this is necessary, but I'm not 
>going to implement that.

Would this solve the problem (and at what cost)?

Any other options open to me? I can solve the ASTS problem by having 
a 10.3 build included in the 10.3 binary installer, but it does put a 
bit of a damper on me other ambitions until I can raise the cost of 
an upgrade or two.

Thanks,

has
-- 
http://freespace.virgin.net/hamish.sanderson/