Re: [gentoo-user] Q: What is "python-exec2c"? Why would "python3" dispatched through it not see an installed copy of pyyaml?

[Neil Bothwick]

On Sun, 7 Mar 2021 11:00:16 -0500, Steven Lembark wrote:

> I believe there isn't any PYTHON_TARGET-ish setting on the system:
>
>      $ grep PYTHON_TARGET /etc/portage/make.conf
> /etc/portage/package.use/*
> /etc/portage/make.conf:#PYTHON_TARGETS="python3_7 python2_7"
> /etc/portage/package.use/dizzy:#*/* PYTHON_TARGETS: python3_6 python3_7
> /etc/portage/package.use/dizzy~:#*/* PYTHON_TARGETS: python3_6 python3_7

There is, just not set by you. There is still the default setting, which
emerge --info will show you is 3.8.

>     $  equery uses dev-python/pyyaml
>     [ Legend : U - final flag setting for installation]
>     [        : I - package is installed with flag     ]
>     [ Colors : set, unset                             ]
>      * Found these USE flags for dev-python/pyyaml-5.4.1:
>      U I
>      - - examples                 : Install examples, usually source
> code
>      + + libyaml                  : enable support for C implementation
> using libyaml
>      - - python_targets_python3_7 : Build with Python 3.7
>      + + python_targets_python3_8 : Build with Python 3.8
>      - - python_targets_python3_9 : Build with Python 3.9
>      - - test                     : Enable dependencies and/or
> preparations necessary to run tests (usually controlled by
>                                     FEATURES=test but can be toggled
> independently) (ins)

libyaml is built for python 3.8 only, as that is the setting you have in
place.

> lembark@dizzy ~ $ eselect python list
>     Available Python interpreters, in order of preference:
>       [1]   python3.9
>       [2]   python3.6
>       [3]   python3.8 (fallback)
>       [4]   python3.7 (fallback)
>       [5]   python2.7 (fallback)
>
>     $ python3 --version;
>     Python 3.9.1

But you have chosen a different default version of Python. That leaves
you two choices:

1) use eselect to set your default python to 3.8
2) Add python_39 to PYTHON_TARGETS
3) Explicitly call python38 in the shebang line of the affected script.
 

-- 
Neil Bothwick

QOTD:
	The only easy way to tell a hamster from a gerbil is that the
	gerbil has more dark meat.