Re: [gentoo-dev] The fallacies of GLEP55

[Ciaran McCreesh]

On Fri, 15 May 2009 14:43:29 -0500
William Hubbs <williamh@g.o> wrote:
> On Thu, May 14, 2009 at 10:53:37PM +0100, Ciaran McCreesh wrote:
> > It can't, because it doesn't know the EAPI until it's sourced the
> > thing using bash. Using things like += in global scope will break
> > older bash versions to the point that they can't reliably extract
> > EAPI.
>
> I just figured out a line in bash that will get an EAPI without
> sourcing the ebuild:
>
> eval `grep '^EAPI=' ebuildfile | head -n 1`
>
> will set EAPI in the current scope to EAPI in the ebuild, without
> sourcing it, unless the issue with something like this would be its
> use of grep and head, but these are both in the system set, so unless
> you don't want to depend on the system set, I don't know what the
> objection would be.

The objection is that your code doesn't work. It's entirely legal to
do, say:

    export EAPI="1"

or:

    inherit versionator

    if version_is_at_least 2 ; then
        EAPI="2"
    else
        EAPI="0"
    fi

Besides, if we were able to do what your code does, we'd just code it
natively, not use external programs.

-- 
Ciaran McCreesh