Re: [docs] [PATCH] dev-manual: correct which package variables support which backends

Hi Robert,

On 6/12/26 1:57 PM, Robert P. J. Day wrote:
> On Fri, 12 Jun 2026, Quentin Schulz wrote:
> 
>> Hi Robert,
>>
>> On 6/12/26 1:33 PM, Robert P. J. Day via lists.yoctoproject.org wrote:
>>>
>>> -The following list introduces variables you can use to prevent packages
>>> -from being installed into your image. Each of these variables only works
>>> -with IPK and RPM package types, not for Debian packages.
>>> -Also, you can use these variables from your ``local.conf`` file
>>> -or attach them to a specific image recipe by using a recipe name
>>> -override. For more detail on the variables, see the descriptions in the
>>> -Yocto Project Reference Manual's glossary chapter.
>>> +There are three variables you can use to avoid installing particular
>>> +packages into the final image -- you can either set these variables
>>> +appropriately in your ``local.conf`` file, or attach them to a specific
>>> +image recipe by using a recipe name override.
>>>
>>
>> What do you mean by "recipe name override"?
> 
>    that phrasing was in the original explanation -- one can set, say,

Not verbatim, and it matters here.

> PACKAGE_EXCLUDE either globally in local.conf:
> 
>    PACKAGE_EXCLUDE = "minicom"
> 
> or attach the exclusion to a specific image by using what the variable

^^^^ here it says "to a specific image" and this patch here says "to a 
specific image recipe".

If you have a recipe name override in an image recipe, it either doesn't 
work or is useless:

my-image.bb:

BAD_RECOMMENDATIONS:pn-my-image = "test"

is unnecessary complexity for what is simply achieved the same with 
BAD_RECOMMENDATIONS = "test".

The phrasing could hint at:

my-image.bb:

BAD_RECOMMENDATIONS:pn-some-package-recipe = "test"

But this doesn't work, because a recipe (including an image recipe) 
variable scope is specific to the recipe and cannot impact another 
recipe, thus this is a no-op.

> glossary describes as a "recipe name override":
> 
> https://docs.yoctoproject.org/ref-manual/variables.html#term-PACKAGE_EXCLUDE
> 
>    PACKAGE_EXCLUDE:pn-<target image> = "minicom"
> 
> so the phrase "recipe name override" comes from the glossary ...
> should it be called something else?
> 

That's ok, it's just combined with the earlier part of the sentence 
which is confusing or misleading (so the other part of the sentence 
needs to be fixed).

Cheers,
Quentin