Re: [docs] [PATCH] ref-manual/system-requirements.rst: add ccache in distros

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

On Mon Aug 31, 2026 at 12:48 PM CEST, Jose Quaresma wrote:
> On Mon, Aug 31, 2026 at 11:26 AM Antonin Godard <antonin.godard@bootlin.com>
> wrote:
>
>> Hi,
>>
>> On Mon Aug 31, 2026 at 11:58 AM CEST, Jose Quaresma via
>> lists.yoctoproject.org wrote:
>> > Looking at the Yocto docs, ccache is missing on Debian/Ubuntu
>> > and OpenSUSE but is in all the others.
>> >
>> > The ccache can improve significantly the builds speeds when we can't
>> > take advantage of the bitbake sstate cache, in such scenario we need
>> > o compile the code. The cache storage needs to be available from the
>> > previous builds so we need to store these ccache artifacts temporary
>> > on our permanent storage.
>> >
>> > The ccache is required to build "-native" packages in oe-core
>> > because it requires HOSTTOOLS += "ccache".
>>
>> Thanks for the patch. Actually, it makes me wonder if we should rather do
>> the
>> opposite and remove this for all distros, as this doesn't sound like a host
>> "requirement" to me.
>>
>
> Yeah, This is opcional and not a requirement as you said.
>
> However, this can greatly improve build time. So it fits in the same
> category as the
> python-websockets, which are not a requirement because upstream hashequiv
> server is not enabled by default, but it also appears listed.

websockets became a requirement when we made the "poky-with-sstate"
bitbake-setup configuration proposed as part of the choices when running
"bitbake-setup init". It would have made no sense to suggest a configuration
with a missing package otherwise.

> To take full advantage of the ccache.bbclass, you need to have the tool in
> the host;
> otherwise, you can only use it for the ":target" arch.

I think this should then be stated in the ccache class documentation, in
documentation/ref-manual/classes.rst. The host requirements should be kept
minimal, IMO.

Antonin