[PATCH] doc: ensure sphinx output is reproducible

[Thomas Monjalon]

06/07/2023 14:49, Christian Ehrhardt:
> On Mon, Jul 3, 2023 at 5:29 PM Thomas Monjalon <thomas at monjalon.net> wrote:
> >
> > 29/06/2023 14:58, christian.ehrhardt at canonical.com:
> > > From: Christian Ehrhardt <christian.ehrhardt at canonical.com>
> > >
> > > By adding -j we build in parallel, to make building on multiprocessor
> > > machines more effective. While that works it does also break
> > > reproducible builds as the order of the sphinx generated searchindex.js
> > > is depending on execution speed of the individual processes.
> > [...]
> > > -if Version(ver) >= Version('1.7'):
> > > -    sphinx_cmd += ['-j', 'auto']
> >
> > What is the impact on build speed on an average machine?
> 
> Hi,
> I haven't tested this in isolation as it was just a mandatory change
> on the Debian/Ubuntu side.
> And the time for exactly and only the doc build is hidden inside the
> concurrency of meson.
> But I can compare a full build [1] and a full build with the change [2].
> 
> That is an average build machine and it is 35 seconds slower with the
> change to no more do doc builds in parallel.

I would prefer adding an option for reproducible build
(which is not a common requirement).