Re: [docs] [PATCH] ref-manual: clarify use of "PACKAGE_ARCH" in a packagegroup

On 6/19/26 7:10 PM, Robert P. J. Day wrote:
> On Fri, 19 Jun 2026, Quentin Schulz wrote:
> 
>> Hi Robert,
>>
>> On 6/16/26 6:46 PM, Robert P. J. Day via lists.yoctoproject.org wrote:
>>>
>>> Warn the developer that if they need to set "PACKAGE_ARCH" in a
>>> custom packagegroup file, that setting must precede the "inherit
>>> packagegroup" line in the packagegroup recipe file.
>>>
>>> Signed-off-by: Robert P. J. Day <[email protected]>
>>>
>>> ---
>>>
>>> diff --git a/documentation/ref-manual/classes.rst
>>> b/documentation/ref-manual/classes.rst
>>> index 95e07f85a..839a89d4b 100644
>>> --- a/documentation/ref-manual/classes.rst
>>> +++ b/documentation/ref-manual/classes.rst
>>> @@ -2130,6 +2130,18 @@ section in the Yocto Project Development Tasks
>>> Manual.
>>>
>>>    Previously, this class was called the ``task`` class.
>>>
>>> +.. note::
>>> +
>>> +   If you're defining a packagegroup and need to set::
>>> +
>>> +      PACKAGE_ARCH = ${MACHINE_ARCH}
>>> +
>>
>> OK so reading this I was like "but who would need to do this? packagegroups
>> are only supposed to include other packages and not compile anything!
>>
>> Then I looked in OE-Core, and there are as many packagegroups with
>> PACKAGE_ARCH set than without. It seems that the need comes from using
>> MACHINE_FEATURES or other knobs that depend on some configuration variable.
>>
>> I think it'd be nice to document this (if not already, but since you're
>> scouring the docs now maybe you'd come across something like that?).
>>
>> I'm thinking this is a big enough footgun that we may want to document the
>> order in the variable glossary as well.
> 
>    richard purdie explained this once upon a time:
> 
> https://lists.openembedded.org/g/openembedded-core/topic/patch_4_4_package_add/87011325
> 

That sounds like a great thing to add to the docs. Both here and in the 
variable glossary for PACKAGE_ARCH as well I think?

Do you agree? Would you mind sending a patch for this?

Cheers,
Quentin