[yocto] Undefining a variable in a recipe?

[Alex J Lennon]

On 01/05/2014 14:54, Paul Eggleton wrote:
> 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)

Thanks for coming back to me on this Paul. OK, I must be
misunderstanding something.

I was outputting the UBOOT_MACHINE to test and it's not a True value at
any point as you
might expect as it's set to the machine type if set, but my build was
still failing to pick up
my preferred recipe version unless I commented out the if/raise, in
which case all worked
as expected.

Caught up with something at the minute but I will go through this  again
first thing tomorrow.

Thanks again,

Alex

> Cheers,
> Paul
>