Re: [RFC] Edk2 BaseTools Python3 Migration Update

[Laszlo Ersek <lersek@redhat.com>]

On 01/07/19 14:41, Gao, Liming wrote:
> Ray:
>  I think this proposal is good to recommend Python3 as the default interpreter. I summary the updated proposal. 
> 
> 1. PYTHON3_ENABLE env is not set. edksetup.bat/edksetup.sh will find higher version python installed in OS. If Python3 is found, Python3 will be used. Then, if python2 is found, and python2 is used. If not found, report error and stop build. This will change the default python interpreter from Python2 to Python3 when they both are installed. 
> 2. PYTHON3_EANBLE env is set to TRUE. edksetup.bat/edksetup.sh will find Python3. If Python3 is found, Python3 will be used. If not found, report error and stop build.
> 3. PYTHON3_ENABLE env is set to not TRUE. edksetup.bat/edksetup.sh will find Python2. If Python2 is found, Python2 will be used. If not found, report error and stop build.
> Once Python is found, edksetup.bat/edksetup.sh and build tool will both print message to let user aware which version python tool is used in this build. 

If we're going for this level of flexibility, I'd like to suggest /
request another improvement. Some Linux distros intend to accommodate
multiple Python3 versions at the same time (this is not a typo; I don't
mean Python2+Python3, but multiple Python3 versions). So basically I'd
suggest that we offer a method for specifying a python version
(2/3/auto-detect), plus, in case a specific major version is specified,
that we allow the user to specify the precise interpreter pathname too.

Thanks,
Laszlo