[U-Boot] Buildman Kconfig issue with consecutive builds

[Simon Glass]

Hi Schrempf,

On Thu, 7 Nov 2019 at 12:14, Schrempf Frieder <frieder.schrempf at kontron.de>
wrote:

> Hi Simon,
>
> On 07.11.19 17:23, Simon Glass wrote:
> > Hi Schrempf,
> >
> > On Thu, 7 Nov 2019 at 08:15, Schrempf Frieder
> > <frieder.schrempf at kontron.de> wrote:
> >>
> >> On 07.11.19 15:02, Bin Meng wrote:
> >>> Hi Frieder,
> >>>
> >>> On Thu, Nov 7, 2019 at 9:28 PM Schrempf Frieder
> >>> <frieder.schrempf at kontron.de> wrote:
> >>>>
> >>>> Hi Bin,
> >>>>
> >>>> On 07.11.19 13:41, Bin Meng wrote:
> >>>>> Hi Schrempf,
> >>>>>
> >>>>> On Thu, Nov 7, 2019 at 12:17 AM Schrempf Frieder
> >>>>> <frieder.schrempf at kontron.de> wrote:
> >>>>>>
> >>>>>> Hi,
> >>>>>>
> >>>>>> I'm having some trouble using buildman to test the impact of some
> >>>>>> Kconfig cleanup patches ([1]).
> >>>>>>
> >>>>>> The patches introduce a new CONFIG_SPL_* option and I try to find
> out
> >>>>>> which defconfigs need to be fixed, by comparing build sizes.
> >>>>>>
> >>>>>> Now when I added a patch to fix a defconfig I noticed that buildman
> >>>>>> wouldn't report the expected size changes and upon looking more
> closely
> >>>>>> I found that the added Kconfig options are still missing in
> u-boot-spl.cfg.
> >>>>>>
> >>>>>> The strange thing is, that when I try to build only the last commit
> then
> >>>>>> the Kconfig options are there, which is why I suspect a bug in
> buildman
> >>>>>> not handling Kconfig changes correctly with consecutive builds.
> >>>>>>
> >>>>>> Can anyone have a look what is wrong or how I can debug this issue?
> >>>>>>
> >>>>>> The issue can be reproduced with the branch at [1], running:
> >>>>>>
> >>>>>> buildman -b spi_flash_kconfig_cleanup_3 --step 0 xilinx_zynqmp_virt
> >>>>>>
> >>>>>
> >>>>> Could you please add "-C" to the buildman command line and have a
> try?
> >>>>
> >>>> Indeed forcing the reconfig between the build steps with '-C' fixes
> the
> >>>> issue.
> >>>>
> >>>> Is it a known problem, that buildman doesn't handle Kconfig changes
> >>>> correctly without '-C' in some cases?
> >>>
> >>> AFAIK, this is an intended design of calling buildman w/o '-C' to save
> >>> some build time.
> >>
> >> Ok, if that's the case I will try to come up with a patch that adds a
> >> note to the README. This has cost me a few hours because I was thinking
> >> buildman does the right thing and Kconfig options are messed up
> somewhere.
> >
> > An incremental build means that it does not run 'make xxx_defconfig'
> > on every commit. Doing it this way saves *a lot* of time for large
> > builds and the main purpose of buildman is to validate that U-Boot
> > builds.
> >
> > However it might be possible to have it both ways...the code fragment
> > below compares the Kconfig files and configs/ directory against the
> > data of the 'u-boot' output file, and could trigger a full rebuild if
> > newer.
>
> Ok, thanks for the explanation.
>
> >
> > If you have time (sounds like you do!), you could incorporate that
> > into buildman.
>
> It's kind of funny that you got the impression, that I have time ;)
> Actually I do not have much time to work on U-Boot in general among all
> the other things.
>
> And now I went deep down into the rabbit hole from "I want to get some
> boards upstreamed" to "I need to port a QSPI controller driver first" to
> "the driver port affects existing CONFIG options that are a total mess
> and need to be fixed" to "I need to run buildman on my cleanup patches"
> to "buildman could need some tweaking".
>
> So unless there will be a lot of rainy weekends, I probably won't start
> working on optimizing buildman ;)
>

May you be plagued with downpours :-)

- Simon