[Distutils] Binary Wheels and "universal" builds on OS-X

[Ronald Oussoren]

On 4 Jun, 2013, at 23:53, Chris Barker - NOAA Federal <chris.barker at noaa.gov> wrote:

> On Tue, Jun 4, 2013 at 9:55 AM, Ronald Oussoren <ronaldoussoren at mac.com> wrote:
> 
>>> $ otool -L python
>>> python (architecture ppc):
>>>      /Library/Frameworks/Python.framework/Versions/2.7/Python
>>> (compatibility version 2.7.0, current version 2.7.0)
>>>      /usr/lib/libmx.A.dylib (compatibility version 1.0.0, current version 47.1.0)
>>>      /usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current
>>> version 88.3.10)
>>> python (architecture i386):
>>>      /Library/Frameworks/Python.framework/Versions/2.7/Python
>>> (compatibility version 2.7.0, current version 2.7.0)
>>>      /usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current
>>> version 88.3.10)
>>> 
>>> (compatibility version of libSystem???)
>>> 
>>> But I imagine there is a cleaner way -- Ronald??
>> 
>> The output of 'otool -l' lists (amongst others) the value of LC_VERSION_MIN_MACOSX which is the deployment target.
> 
> I don't see that on my machine -- is that "l", a lower-case "el'?

The option or the LC_VERSION_MIN_MACOSX value? I'm running OSX 10.8, where both are available, but according to Google LC_VERSION_MIN_MACOSX was introduced in a 10.6 subrelease. Without that load command you cannot easily see what the deployment target is (the best way I find while writing would be a tool that checks library load commands and the list of symbols used with a to-be-maintained registry).

> 
>> Both can also be found using macholib ;-)
> 
> probably best not to add another dependency.
> 
> But I've lot track on why we'd need this -- presumably the wheel
> builder would know what it built, and could supply the proper
> meta-data, and that would be that.

You don't need this, distutils (and hence setuptools) already knows this information and other build tools can also know this.

Ronald

> 
> -Chris
> 
> 
> 
> 
> 
> -- 
> 
> Christopher Barker, Ph.D.
> Oceanographer
> 
> Emergency Response Division
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> 
> Chris.Barker at noaa.gov