[yocto] Undefining a variable in a recipe?

[Paul Eggleton]

Hi Alex,

On Thursday 01 May 2014 10:42:51 Alex J Lennon wrote:
> I have an issue with the build of an old u-boot (2009.08) which is
> failing a check in poky as both UBOOT_CONFIG and UBOOT_MACHINE are being
> defined for some reason.
> 
> poky/meta/classes/uboot-config.bbclass
> 
>  ubootmachine = d.getVar("UBOOT_MACHINE", True)
>  ubootconfigflags = d.getVarFlags('UBOOT_CONFIG')
> 
> ..
> 
>  if ubootmachine and ubootconfigflags:
>        raise bb.parse.SkipPackage("You cannot use UBOOT_MACHINE and
> UBOOT_CONFIG at the same time.")
> 
> 
> I have a .bbappend on the original u-boot recipe and could solve the
> problem by undefining UBOOT_MACHINE if I could work out how to do this
> in the .bbappend
> 
> I've tried setting it to None or an empty string, and I tried an
> anonymous python function but those approaches didn't help,
> 
> e.g. (in the .bbappend
> 
> UBOOT_MACHINE = ""

This should work - the python code above is checking if the value evaluates to 
True, and that shouldn't be the case for an empty string. I suspect something 
else is at work here - either the check is running before your value gets set, 
or the value is being set using an override somewhere and therefore your value 
isn't being used.

(adding Otavio on CC since these are his checks and his layer)

Cheers,
Paul

-- 

Paul Eggleton
Intel Open Source Technology Centre