Re: [docs] [PATCH 2/2] dev-manual/start.rst: remove shared PERSISTENT_DIR mentions

["Antonin Godard" <antonin.godard@bootlin.com>]

On Tue Jul 15, 2025 at 5:55 PM CEST, Alexander Kanavin wrote:
> On Tue, 15 Jul 2025 at 11:56, Antonin Godard via
> lists.yoctoproject.org
> <antonin.godard=bootlin.com@lists.yoctoproject.org> wrote:
>
>> +    -  Set up a local :ref:`overview-manual/concepts:Hash Equivalence` server
>> +       with :term:`BB_HASHSERVE` and :term:`BB_SIGNATURE_HANDLER`. A basic setup
>> +       would be::
>> +
>> +          BB_HASHSERVE = "auto"
>> +          BB_SIGNATURE_HANDLER = "OEEquivHash"
>
> This is still problematic and should be clarified further:
>
> 1. BB_HASHSERVE and BB_SIGNATURE_HANDLER do not set up or start a
> server, they set up the hash equivalence client built into bitbake.
>
> 2. The above client configuration (used by poky) also starts a private
> server that is specific to a particular build directory. So hash equiv
> information would not be shared between multiple build directories,
> and this will cause sstate mismatches (as reported in the bug), if
> sstate is shared.
>
> Maybe it's easier to just remove the above, and only refer to the hash
> equiv section in the other manual:
>
> +    -  Set up a local :ref:`overview-manual/concepts :Hash Equivalence` server
> +
> +       See the :ref:`overview-manual/concepts:Hash Equivalence` section of the
> +       Yocto Project Overview and Concepts Manual for more details on the hash
> +       equivalence feature.
>
> Then we can do a correct, comprehensive description there.

Yes, I also feel that hash equivalence could deserve its own document, and
should go further than a server/client local to the build directory only. Thanks
for the clarification.

I will try to work on this soon, at least for now the shared PERSISTENT_DIR
mention is reverted, which is good.

Antonin

-- 
Antonin Godard, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com