[gentoo-python] Re: [PATCH python-r1 2/2] Introduce PYTHON_COMPAT_OVERRIDE to make testing easier.

[Mike Gilbert]

On Sun, Mar 17, 2013 at 6:33 PM, Michał Górny <mgorny@g.o> wrote:
> The PYTHON_COMPAT_OVERRIDE can be set in the environment to enforce
> a different set of Python implementations than one being intersection
> of PYTHON_COMPAT and PYTHON_TARGETS.
>
> Due to technical limitations, the variable influences only the list
> of implementations actually used. USE flags, dependencies and other
> metadata variables are not modified.
> ---
>  gx86/eclass/python-r1.eclass | 34 ++++++++++++++++++++++++++++++++++
>  1 file changed, 34 insertions(+)
>
> diff --git a/gx86/eclass/python-r1.eclass b/gx86/eclass/python-r1.eclass
> index 99bd240..c060c24 100644
> --- a/gx86/eclass/python-r1.eclass
> +++ b/gx86/eclass/python-r1.eclass
> @@ -74,6 +74,25 @@ if ! declare -p PYTHON_COMPAT &>/dev/null; then
>         fi
>  fi
>
> +# @ECLASS-VARIABLE: PYTHON_COMPAT_OVERRIDE
> +# @INTERNAL
> +# @DESCRIPTION:
> +# This variable can be used when working with ebuilds to override
> +# the in-ebuild PYTHON_COMPAT. It is a string listing all
> +# the implementations which package will be built for. It need be
> +# specified in the calling environment, and not in ebuilds.
> +#
> +# It should be noted that in order to preserve metadata immutability,
> +# PYTHON_COMPAT_OVERRIDE does not affect IUSE nor dependencies.
> +# The state of PYTHON_TARGETS is ignored, and all the implementations
> +# in PYTHON_COMPAT_OVERRIDE are built. Dependencies need to be satisfied
> +# manually.
> +#
> +# Example:
> +# @CODE
> +# PYTHON_COMPAT_OVERRIDE='pypy2_0 python3_3' emerge -1v dev-python/foo
> +# @CODE
> +
>  # @ECLASS-VARIABLE: PYTHON_REQ_USE
>  # @DEFAULT_UNSET
>  # @DESCRIPTION:
> @@ -576,6 +595,21 @@ _python_check_USE_PYTHON() {
>  # @DESCRIPTION:
>  # Set up the enabled implementation list.
>  _python_obtain_impls() {
> +       if [[ ${PYTHON_COMPAT_OVERRIDE} ]]; then
> +               if [[ ! ${_PYTHON_COMPAT_OVERRIDE_WARNED} ]]; then
> +                       ewarn "WARNING: PYTHON_COMPAT_OVERRIDE in effect. The following Python"
> +                       ewarn "implementations will be enabled:"
> +                       ewarn
> +                       ewarn " ${PYTHON_COMPAT_OVERRIDE}"
> +                       ewarn
> +                       ewarn "Dependencies won't be satisfied, and PYTHON_TARGETS will be ignored."
> +                       _PYTHON_COMPAT_OVERRIDE_WARNED=1
> +               fi
> +
> +               MULTIBUILD_VARIANTS=( ${PYTHON_COMPAT_OVERRIDE} )
> +               return
> +       fi
> +
>         _python_validate_useflags
>         _python_check_USE_PYTHON
>
> --
> 1.8.1.5
>

This could be quite handy.