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From: Paul Eggleton <paul.eggleton@linux.intel.com>
To: Gary Thomas <gary@mlbassoc.com>
Date: Fri, 16 Nov 2012 14:24:39 +0000
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Subject: Re: Wacky dependencies
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On Friday 16 November 2012 07:12:38 Gary Thomas wrote:
> I wanted to run an experiment with X11 vs GTK-directfb on my platform.
> I built a complete image with X11 in DISTRO_FEATURES.
> When I changed DISTRO_FEATURES to have gtk-directfb, nearly everything
> was rebuilt!  Why on earth do GCC & EGLIBC have to be rebuilt??  This
> doesn't seem logical at all to me.

The build system is not able to determine whether a variable within a recipe 
depends on a single value within DISTRO_FEATURES, it only knows that it looks 
at the variable; thus any change to DISTRO_FEATURES will change the hash of 
all recipes that read DISTRO_FEATURES.

I'd like to fix this but given that we check if DISTRO_FEATURES and other list 
variables like it contain values using inline python code i.e. 
${@base_contains(...)} this seems like it would be tricky to implement in a 
reliable way.

Cheers,
Paul

-- 

Paul Eggleton
Intel Open Source Technology Centre