Re: [PATCH] doc: ensure sphinx output is reproducible

[Thomas Monjalon <thomas@monjalon.net>]

17/05/2024 13:29, Luca Boccassi:
> On Mon, 27 Nov 2023 at 17:04, Bruce Richardson
> <bruce.richardson@intel.com> wrote:
> >
> > On Mon, Nov 27, 2023 at 05:45:52PM +0100, Thomas Monjalon wrote:
> > > 06/07/2023 14:49, Christian Ehrhardt:
> > > > On Mon, Jul 3, 2023 at 5:29 PM Thomas Monjalon <thomas@monjalon.net> wrote:
> > > > >
> > > > > 29/06/2023 14:58, christian.ehrhardt@canonical.com:
> > > > > > From: Christian Ehrhardt <christian.ehrhardt@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).
> > >
> > Taking a slightly different tack, is it possible to sort the searchindex.js
> > file post-build, so that even reproducible builds get the benefits of
> > parallelism?
> 
> Given the recent attacks with malicious sources being injected in open
> source projects, reproducible builds are more important than ever and
> should just be the default.

Yes it should be the default when packaging.
Why should it be the default for normal builds?

> Could we please take this patch as-is?

It's a pity nobody tried a different approach.
Considering the activity on this, it does not look a high priority.

> If someone wants to try and fix this searchindex.js in a different way
> separately it can then be done later and on top of this.

Removing something and ask others to re-add it later is a strange reasoning.