Re: [PATCH] build/docs: move docstring prereq to file targets

[David Bremner <david@tethera.net>]

Tomi Ollila <tomi.ollila@iki.fi> writes:

> On Wed, Dec 09 2020, David Bremner wrote:
>
>> Under a sufficiently high level of parallelism [1] there seems to be a
>> a race condition that allows sphinx-build to start running before the
>> docstrings are extracted. This change moves the docstring stamp from
>> the phony targets sphinx-html and sphinx-info to the file targets that
>> they depend on. I'm not sure why this makes things better, but I am
>> fairly confident it does not make things worse, and experimentally it
>> seems to eliminate the race condition.
>
> Good enough for me if this helps. I also don't see reason why that would
> make things better (and probably not things worse), just that I got
> headache reading that Makefile ;) (and, for example, these particular
> targets mentioned would not need to be marked .PHONY...)
>
> I'd suggest to monitor the behaviour for a while and if things are
> consistently better then merge -- such a things when we don't know
> enough experience may be enough (or someone(tm) could try to parse make
> debug logs ;/) -- or someone(tm) may tell us why that heleps :D

I'll try a test upload to Debian and see if that fixes the problem
there. I did 2000 builds (sortof by mistake) at -j32 on a 16 thread / 8
core machine, with no crashes. Much less parallelism than the original
report, but lots of repetition.

d