Re: [bitbake-devel] [PATCH RFC 2/3] build: Attach a log catcher to tasks and save their records

["Mathieu Dubois-Briand" <mathieu.dubois-briand@bootlin.com>]

On Sun Oct 25, 2026 at 3:15 PM CET, Richard Purdie wrote:
> On Sat, 2026-10-24 at 14:33 +0200, Mathieu Dubois-Briand via lists.openembedded.org wrote:
>> Every task gets a LogCatcher which records its warnings and errors during
>> execution. Right after the task body, and before the postfuncs, the
>> records are written to ${T}/logrecords.<task>.json. The sstate packaging
>> postfunc reads the current task's file to bundle the messages for replay
>> when the task is later restored from the sstate cache.
>> 
>> Writing the file before the postfuncs makes both the current task's own
>> record and the files of already finished dependency tasks readable from
>> the same place.
>> 
>> AI-Generated: Uses opencode (DeepSeek V4 Flash)
>> Signed-off-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>
>> ---

...

>> @@ -711,6 +720,9 @@ def _exec_task(fn, task, d, quieterr):
>>              for func in (prefuncs or '').split():
>>                  exec_func(func, localdata)
>>              exec_func(task, localdata)
>> +            if tasklogcatcher.records:
>> +                with open(logrecords, 'w') as f:
>> +                    json.dump(tasklogcatcher.records, f)
>>              for func in (postfuncs or '').split():
>>                  exec_func(func, localdata)
>
> I was going to ask if this should unconditionally rewrite the file even
> if there are no records, else messages might persist if you fix
> warnings output for example? I then see you delete the file above.
>
> If there is no log output, I guess the question is whether we should
> write an empty file or not...
>

I had no strong opinion here, but based on your comment, I feel like we
should indeed write an empty file when there is no log.

Thanks,
Mathieu

-- 
Mathieu Dubois-Briand, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com