[CMake] cmake vs. Python 3.4

[Scott Kitterman]

On Friday, December 23, 2016 12:53:30 PM Alan W. Irwin wrote:
> On 2016-12-23 20:57+0100 Lev wrote:
> > Hi list,
> > 
> > 
> > I have this:
> > 
> > FIND_PACKAGE(PythonInterp)
> > 
> > and cmake finds this:
> > 
> > -- Found PythonInterp: /usr/bin/python (found version "2.7.9")
> > 
> > However, 3.4 is also installed. How can I specify to find 3.4?
> > 
> > If I say:
> > 
> > set(Python_ADDITIONAL_VERSIONS 3.4)
> > FIND_PACKAGE(PythonInterp 3 REQUIRED)
> > 
> > still no luck.
> > 
> > This is on a Debian stable, so
> > 
> > $ cmake --version
> > cmake version 3.0.2
> 
> Try using the update-alternatives command so that "python" becomes
> symbolically linked to python-3.4 rather than python-2.7.9
> 
> Or uninstall python 2.7.9.

No.  Don't do that.  Debian (and its derivatives don't work that way).

The way I've done this before (when building for multiple python and python3 
versions is to set:

PYTHON_EXECUTABLE=/usr/bin/python$v

Where $v would, in your case, be 3.4.

Scott K