[yocto] Disabling ipv6

[Paul Eggleton]

On Tuesday 27 October 2015 08:45:26 Burton, Ross wrote:
> On 26 October 2015 at 20:16, Todd Efflam <todd.efflam at gmail.com> wrote:
> > Thanks for the tip.  We tried adding this to the local.conf file but
> > it failed with the following error:
> > ERROR: Nothing PROVIDES 'glibc'
> > ERROR: glibc was skipped: missing required distro feature 'ipv6' (not
> > in DISTRO_FEATURES)
> 
> Ouch.  That's surely not right.
> 
> The commit that introduced this was:
> 
> commit 97899bc908a421295d814801ff86edeb9304d2fd
> Author: Chen Qi <Qi.Chen at windriver.com>
> Date:   Thu Jul 3 11:23:42 2014 +0800
> 
>     eglibc: check for required distro features
> 
>     If users accidently override the DISTRO_FEATURES in local.conf,
>     then build failures occur for lack of libc functions.
> 
>     All features in DISTRO_FEATURES_LIBC should be in DISTRO_FEATURES.
>     That's why this patch let the recipe inherit distro_features_check
>     class and set REQUIRED_DISTRO_FEATURES to "${DISTRO_FEATURES_LIBC}".
> 
>     [YOCTO #6381]
> 
> But the entire point of the logic in glibc-options is to make these
> options, well, optional.
> 
> It looks like the required_distro_features use in eglibc is misguided.  Can
> you comment out the REQUIRED_DISTRO_FEATURES assignment in glibc.inc and
> verify that it then builds fine without ipv6 enabled?

Ah yes, I meant to get back to this at some point as I didn't really like how 
this was fixed previously either (see 
https://bugzilla.yoctoproject.org/show_bug.cgi?id=6381 for details of the 
problem). It seems to me that we should:

1) Fix the glibc recipes so that they handle an empty libc configuration or 
error out much earlier with a sensible message if that's not possible

2) Properly detect when DISTRO_FEATURES has been "zapped" via += in local.conf 
or elsewhere and show an error/warning about that.

Cheers,
Paul

-- 

Paul Eggleton
Intel Open Source Technology Centre