[Buildroot] [RFC 0/2] Handle conflicting files with Busybox

[Thomas Petazzoni <thomas.petazzoni@free-electrons.com>]

Hello,

Thanks for the feedback.

On Thu, 28 Dec 2017 18:00:17 +0100, Yann E. MORIN wrote:

> > This RFC series is an attempt at solving this problem for Busybox. I
> > have not fixed all packages yet: since it is a very boring task to do,
> > I wanted to first get some feedback on whether the approach looks
> > reasonable or not.
> > 
> > If the feedback is positive, I'll go ahead and submit proper patches
> > that fix all packages that conflict with Busybox.  
> 
> As I previously said on IRC: I do not much like the big list we will now
> have to maintain; that's sad...

Even though I agree it's not nice to maintain, I think it's unavoidable
if we want to solve the overwriting issue.

> However, I like the fact that we can get rid of the many dependencies in
> so many packages here and there. :-)
> 
> What I would have suggested, though, is to do what Baruch hinted at: use
> the noclobber install of Busybox, and then have Busybox depend on all
> the packages it provides applets for:
> 
>     BUSYBOX_DEPENDENCIES = \
>         $(if $(BR2_PACKAGE_COREUTILS),coreutils) \
>         $(if $(BR2_PACKAGE_util_LINUX),util-linux) \
>         etc...
> 
> But unfortunately, the noclobber install option is not usable:
> 
>   - first, there is no way to cause a noclobber install;
> 
>   - second, the noclobber is not accounted for in the case shell
>     wrappers are used.
> 
> So, I'm afraid we don't have much choice but to do as your series
> does...

There is however one remaining debate: my patch series tweaks the
Busybox configuration to not build the support for applets for which
the functionality is provided by a full-featured program. But Baruch
didn't like this tweaking of the Busybox configuration, and would
prefer to not install the symlinks, and leave the Busybox configuration
unchanged (which means we have lots of Busybox applets built into
Busybox that are not really used on the target).

Do you have an opinion on this specific topic ?

Another question is whether we want to have this logic centralized in
busybox.mk, or spread into the packages that provide the full-featured
variants of the applets ? The latter may have some variable definition
ordering issues though.

Thanks,

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com