Re: [docs] "Required Variables" aren't really "required"

On Fri, 5 Jun 2026, Richard Purdie wrote:

> On Fri, 2026-06-05 at 07:22 -0700, Robert P. J. Day via lists.yoctoproject.org wrote:
> > On Fri, 5 Jun 2026, Antonin Godard via lists.yoctoproject.org wrote:
> >
> > > On Fri Jun 5, 2026 at 1:40 PM CEST, Robert P. J. Day wrote:
> > > >
> > > > here:
> > > >
> > > > https://docs.yoctoproject.org/contributor-guide/recipe-style-guide.html#required-variables
> > > >
> > > > the section "Required Variables" goes on to say that four variables
> > > > "should" be included in all recipes ("should" does not equal "must"),
> > > > but a quick test build showed that none of those four variables seemed
> > > > to be required for successful parsing -- only a missing "LICENSE"
> > > > triggered a parse error during my testing.
> > >
> > > What do you suggest as an alternative word for "Required"?
> >
> >   Well, it makes no sense to first say that short list of variables is
> > "Required", then say they "should" be included in all recipes. It's
> > common usage that "should" means only that something is *recommended*
> > or *encouraged*, not mandatory.
> >
> >   Then based on my testing, none of those variables are actually
> > required since leaving them out didn't cause a parse error. So I don't
> > know how people would want to word that or what it should say.
>
> LICENSE is effectively required and should be in the required section.
> SUMMARY/DESCRIPTION are also strongly encouraged else they get defaults
> which aren't particularly useful. I thought there were QA checks for
> those? Perhaps the QA tests are limited just to oe-core by default?
>
> I think saying they're required is fine to be honest. LICENSE should be
> moved to the required section.
>
> HOMEPAGE is also strongly recommended, again. Perhaps the section
> should be:
>
> """
> The following variables should be included in all recipes:
>
> LICENSE, DESCRIPTION, SUMMARY
>
> It is also strongly recommended to set:
>
> HOMEPAGE, BUGTRACKER
> """
>
> Would that be more acceptable to you?

  i'll post one more note on this and then let it go. as a test, i
tweaked the OE-Core "bc" recipe to see what was *truly* required for a
recipe in the openembedded-core layer, and here are the results which
differ slightly from what one reads here:

https://docs.yoctoproject.org/contributor-guide/recipe-style-guide.html#recipe-metadata

  in the "bc" recipe, i wiped out most of the metadata and learned
that parsing does indeed require the LICENSE and LIC_FILES_CHKSUM
fields (that section does not mention that LIC_FILES_CHKSUM is not
required if LICENSE is "CLOSED", but that is mentioned in the
variables glossary).

  beyond that, i deleted all of SUMMARY, HOMEPAGE, DESCRIPTION and
SECTION, ran "bitbake -p bc", and got only two warnings:


WARNING: bc-1.08.2-r0 do_recipe_qa: QA Issue: Recipe bc in
/home/rpjday/oe/layers/openembedded-core/meta/recipes-extended/bc/bc_1.08.2.bb
does not contain a SUMMARY. Please add an entry. [missing-metadata]
WARNING: bc-1.08.2-r0 do_recipe_qa: QA Issue: Recipe bc in
/home/rpjday/oe/layers/openembedded-core/meta/recipes-extended/bc/bc_1.08.2.bb
does not contain a HOMEPAGE. Please add an entry. [missing-metadata]


which are, in fact, the two metadata variables examined in
do_recipe_qa().

  and given the various defaults for stuff like SUMMARY and
DESCRIPTION and so on, it seems that LICENSE and LIC_FILES_CHKSUM is
the only *truly* required metadata, and everything else is simply
strongly encouraged or will be quietly set to a default value as
defined in bitbake.conf.

rday