Re: [RFC] Edk2 BaseTools Python3 Migration Update

[Laszlo Ersek <lersek@redhat.com>]

On 01/08/19 15:22, Gao, Liming wrote:
> Laszlo:
>   Yes. This can be supported. But, I don't know what purpose to
>   specify python minor version of Python3. Current implementation in
>   Python3 branch always tries to find the high version installed in
>   OS. For example, Python3.4, Python3.7 are both installed, Python3.7
>   will be chosen. Does this policy meet with your usage?

Not really; please see paragraph (c) in my other reply at
<https://lists.01.org/pipermail/edk2-devel/2019-January/034762.html>.

The rationale is given in the blog post at
<https://developers.redhat.com/blog/2018/11/14/python-in-rhel-8/>, near
the "platform-python" mentions. Basically the OS should be able to offer
different Python3 installations (at the same time) to end-users and
internally to OS-level packages.

Thanks!
Laszlo


>> -----Original Message-----
>> From: Laszlo Ersek [mailto:lersek@redhat.com]
>> Sent: Tuesday, January 8, 2019 3:04 AM
>> To: Gao, Liming <liming.gao@intel.com>; Ni, Ray <ray.ni@intel.com>;
>> edk2-devel@lists.01.org; leif.lindholm@linaro.org; afish@apple.com;
>> Kinney, Michael D <michael.d.kinney@intel.com>
>> Subject: Re: [edk2] [RFC] Edk2 BaseTools Python3 Migration Update
>>
>> 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