From mboxrd@z Thu Jan  1 00:00:00 1970
From: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Date: Sun, 31 May 2020 15:10:20 +0200
Subject: [Buildroot] [for-next] package/rust: allow using python3
 interpreter
In-Reply-To: <49ffaaec-73fe-0cd0-9a4d-ff920f5c2562@gmail.com>
References: <20200526182037.592824-1-romain.naour@gmail.com>
 <20200529231401.4c66c5d9@windsurf.home>
 <49ffaaec-73fe-0cd0-9a4d-ff920f5c2562@gmail.com>
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On Fri, 29 May 2020 23:45:23 +0200
Romain Naour <romain.naour@gmail.com> wrote:

> > Shouldn't we try to find an upstreamable solution here, such as perhaps
> > a PYTHON environment variable, or an argument to configure that allows
> > to specify the path to the Python interpreter ?
> > 
> > But in fact, this path to the Python interpreter is already in the
> > config.toml file that we generate, why isn't this path used ?  
> 
> humm, It seems that this configure script is not used at all by rust package
> since we use directly x.py...
> So we can just drop this patch.

Could you send a follow-up patch ?

> >> +ifeq ($(BR2_PACKAGE_PYTHON3),y)
> >> +HOST_RUST_PYTHON_VERSION = $(PYTHON3_VERSION_MAJOR)
> >> +HOST_RUST_DEPENDENCIES += host-python3
> >> +else
> >> +HOST_RUST_PYTHON_VERSION = $(PYTHON_VERSION_MAJOR)
> >> +HOST_RUST_DEPENDENCIES += host-python
> >> +endif  
> > 
> > I think we should start inverting this logic, i.e use host-python3 by
> > default if there is no python interpreter selected for the target. We
> > should do that not only here, but in all packages that have a logic
> > like that: python3 should become our default, and python2 should become
> > the exception.  
> 
> Yes, with this change we can remove python3-<module> added to provide python3
> modules. I hope packages that still use python2 will only require the python2
> interpreter without any additional modules.

That is not what I meant. What I meant was to change:

ifeq ($(BR2_PACKAGE_PYTHON3),y)
HOST_RUST_PYTHON_VERSION = $(PYTHON3_VERSION_MAJOR)
HOST_RUST_DEPENDENCIES += host-python3
else
HOST_RUST_PYTHON_VERSION = $(PYTHON_VERSION_MAJOR)
HOST_RUST_DEPENDENCIES += host-python
endif  

to:

ifeq ($(BR2_PACKAGE_PYTHON),y)
HOST_RUST_PYTHON_VERSION = $(PYTHON_VERSION_MAJOR)
HOST_RUST_DEPENDENCIES += host-python
else
HOST_RUST_PYTHON_VERSION = $(PYTHON3_VERSION_MAJOR)
HOST_RUST_DEPENDENCIES += host-python3
endif  

i.e: our default becomes python3.

Thomas
-- 
Thomas Petazzoni, CTO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com