[yocto] ROOTFS_RPM_DEBUG undocumented

[Paulo Neves]

I will propose a patch with a default bb.debug, and always have the
verbose on dnf. Let's see how it affects the performance. I cannot
test this in a docker container because of the problems described
below:

In the mean time I found what was happening with my slow do_rootfs. I
was running bitbake with RPM packaging in a docker instance. It seems
there is a problem with RPM/dnf in bitbake where it is extremely slow
inside a docker container (1 file per second). After changing to IPK
packages everything went smoothly.

Others have had the same problem[1]. I will later report this to
openembedded mailing list as this effectively makes RPM unusable in a
container. I will also provide a Dockerfile to reproduce this problem.

[1] https://github.com/moby/moby/issues/23137#issuecomment-359097008

Paulo Neves

On Thu, May 3, 2018 at 3:03 PM, Alexander Kanavin
<alexander.kanavin at linux.intel.com> wrote:
> On 05/03/2018 01:42 PM, Paulo Neves wrote:
>>
>> # Add ROOTFS_RPM_DEBUG to the documentation;
>
>
> I'd rather get rid of it, the less variables the better :)
>
>> # Detect if we are running with debug output and enable the debugging
>> output. This is the most elegant solution but I do not know how to
>> detect if debug log level is turned on;
>
>
> I don't think you are meant to detect that; bitbake's debug level is not
> meant to affect what is being printed, but merely whether it's printed or
> discarded.
>
>> # Have dnf always print in verbose mode and print the output to
>> bb.debug instead of bb.note.
>
>
> I think this is the best solution actually.
>
>> I am happy to provide a patch upon decision or suggestions.
>
>
> Thank you :) Do measure the performance before and after as we don't want to
> introduce a significant slowdown here.
>
>
> Alex