[yocto] Python Error in SDK

[Paul Eggleton]

Hi Erik,

On Tuesday 07 April 2015 06:44:01 Erik Bolton wrote:
> This has been brought up before (although I think the error was different),
> but I'm having a lot of issues with the version of Python included with the
> SDK.
> 
> We use Python for code generation as part of our project. If I source the
> environment script and try to run our Python scripts I get this:
> 
> Traceback (most recent call last):
>   File
> "/opt/poky/1.7.1/sysroots/x86_64-pokysdk-linux/usr/lib/python2.7/site.py",
> line 569, in <module> main()
>   File
> "/opt/poky/1.7.1/sysroots/x86_64-pokysdk-linux/usr/lib/python2.7/site.py",
> line 551, in main known_paths = addusersitepackages(known_paths)
>   File
> "/opt/poky/1.7.1/sysroots/x86_64-pokysdk-linux/usr/lib/python2.7/site.py",
> line 278, in addusersitepackages user_site = getusersitepackages()
>   File
> "/opt/poky/1.7.1/sysroots/x86_64-pokysdk-linux/usr/lib/python2.7/site.py",
> line 253, in getusersitepackages user_base = getuserbase() # this will also
> set USER_BASE
>   File
> "/opt/poky/1.7.1/sysroots/x86_64-pokysdk-linux/usr/lib/python2.7/site.py",
> line 242, in getuserbase from sysconfig import get_config_var
>   File
> "/opt/poky/1.7.1/sysroots/x86_64-pokysdk-linux/usr/lib/python2.7/sysconfig.
> py", line 10, in <module> 'stdlib':
> '{base}/'+sys.lib+'/python{py_version_short}',
> AttributeError: 'module' object has no attribute 'lib'
> 
> If I try running something that doesn't exist I get this:
> 
> Fatal Python error: Py_Initialize: Unable to get the locale encoding
> ImportError: No module named 'encodings'
> Aborted (core dumped)
> 
> I've tried using update-alternatives to point the SDK python to my local
> python (Ubuntu 14.10, Python 2.7.8), but the errors persist.
> 
> I know a few people have simply deleted the python binary from the SDK, but
> I don't think that will help in my case.
> 
> I would try to remove it from the SDK in the actual package groups, but
> smartpm and a few other programs depend on it. I'm not sure they would play
> nice with my local version.
> 
> Any suggestions on how to fix this "correctly"?

Basically when python (technically, "nativesdk-python" when talking about the 
SDK) gets pulled in, that's the minimal python core and not all of the modules 
in the normal Python distribution, resulting in failures such as these. You 
can add those however by adding the following either in your image recipe (if 
using -c populate_sdk) or in your configuration:

  TOOLCHAIN_HOST_TASK_append = " nativesdk-python-modules"

Rebuild and re-install the SDK and things should work a bit better after that.

Cheers,
Paul

-- 

Paul Eggleton
Intel Open Source Technology Centre