Re: [PATCH v2 2/2] vim: set PACKAGECONFIG idiomatically

Andre McCurdy

On Fri, Dec 3, 2021 at 2:06 AM Richard Purdie
<richard.purdie@...> wrote:

On Fri, 2021-12-03 at 01:39 -0800, Andre McCurdy wrote:
On Wed, Dec 1, 2021 at 2:33 PM Richard Purdie
<richard.purdie@...> wrote:

On Tue, 2021-11-30 at 13:45 -0800, Andre McCurdy wrote:
On Tue, Nov 30, 2021 at 1:20 PM Ross Burton <ross@...> wrote:

On Tue, 30 Nov 2021 at 19:32, Andre McCurdy <armccurdy@...> wrote:
This isn't equivalent - it will cause a change in behaviour for anyone
using PACKAGECONFIG += "foo" from a .bbappend.
Correct, but this is likely the only recipe in the greater ecosystem
which has this behaviour, so I'm not that bothered to be honest. :)
The only recipe? There are many recipes which set a default
PACKAGECONFIG with ?= and many which set it with ??=. Your change is
effectively switching the vim recipe from one approach to the other.
The fact that adding PACKAGECONFIG options from a .bbappend with +=
sometimes works OK and sometimes not is a source of confusion for new

You are right that no one seems to care though...
Some of us very much do care, it is actually bothering me a lot and I've posted
several times on the architecture list about this kind of issue.

We haven't worked out what we can agree to do about it though :(.
As a first, very easy, step, make a statement here on the mailing list
that all PACKAGECONFIG defaults should be assigned with ?= instead of
??= and fix the recipes in oe-core accordingly.
The question is whether we all agree on that and I'm not sure we all do.
What are the possible objections?

As a second step, the parser could generate a warning (or even an
error) if any variable is assigned to with only ??= and += (the end
result of that combination is not what any user would expect and I
doubt if any legitimate use case relies on it).
Would be interesting to see if there is valid use so it is probably worth some
tests/analysis. The ??= operator never did what I'd hoped it would in reality
I agree ??= is way overused and very often in places where ?= or a
direct assignment would be better. I'm not the one accepting and
merging patches though... you are!

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