Re: [Visualpython-users] [Fwd: Re: non standard install of vpython-4.beta16]

[Jaap S. <j....@hc...>]

Martin Costabel wrote:

> 
> This whole problem has nothing to do with vpython, or only insofar as it 
> uses libboost_python for building. It is a libboost_python problem. 
> Libboost_python uses (by default) unicode, and therefore it needs to be 
> linked together with the same flavor of python, UCS2 or UCS4, that it 
> was built with.
> 
>  From the original post it seems clear that there were two pythons 
> present on the machine, the one from SAGE which believes in UCS2, and 
> the one from the linux distribution which believes in UCS4. The 
> libboost_python was built against the UCS4 python, so it cannot be used 
> with UCS2 python. In other words, if you want to build vpython with the 
> python from SAGE, you first have to build libboost_python with the same 
> python.
> 
> After reading up on this story, I still find it incredible that the 
> python developers consciously decided to allow python to adhere to one 
> of two incompatible persuasions, UCS2 and UCS4, so that compiled modules 
> (extensions) must adhere to the same persuasion as the python they were 
> built with, or they will crash. What is worse is that you don't see from 
> the outside which persuasion your python was built with, unless you run 
> something like
> 
>   python -c 'import sys; print sys.maxunicode'
> 
> or you search for UCS2 or UCS4 in symbol names in the binary executable.
> 
> AFAICT, UCS2 is still the default, i.e. you get this if you don't use 
> any --unicode configure flag.
> 

Thanks! I don't like building boost. The more easy way to go, I think,
is rebuilding the Python in SAGE with UCS4.

Jaap