Re: DISTRO is set too late

[Harald Seiler <hws@denx.de>]

On Thu, 2018-10-25 at 14:21 +0100, Jan Kiszka wrote:
> On 23.10.18 13:37, Harald Seiler wrote:
> > On Tue, 2018-10-23 at 14:34 +0300, Maxim Yu. Osipov wrote:
> > > On 10/23/18 1:10 PM, Harald Seiler wrote:
> > > > On Tue, 2018-10-23 at 12:48 +0300, Maxim Yu. Osipov wrote:
> > > > > Hi Harald,
> > > > > 
> > > > > The list of supported distros is under isar/meta-isar/conf/distro/*.conf
> > > > > (debian-wheezy is officially not supported but still present for
> > > > > convenience).
> > > > 
> > > > We are using `debian-stretch`.  If I add
> > > > 
> > > >       DISTRO = "debian-stretch"
> > > > 
> > > > to `local.conf`, I can build.  But this should not be necessary as
> > > > $DISTRO is also set from multiconf.  The issue is that this happens
> > > > too late, so when $DISTRO_SUITE is expanded, it hasn't happened yet.
> > > > 
> > > > > How did you get the value `poky` for DISTRO in your environment?
> > > > 
> > > > Hmm, apparently this is kas adding
> > > > 
> > > >       DISTRO ??= "poky"
> > > > 
> > > > to `local.conf` if no distro is supplied in its config.  This should,
> > > > again, not be an issue, because the multiconf sets
> > > > 
> > > >       DISTRO ?= "debian-stretch"
> > > > 
> > > > What seems to go wrong is that the multiconf is read too late, so
> > > > that base-apt-helper.bb tries to expand $DISTRO before is has gotten
> > > > its final value.  I don't think this is the intended behavior ...
> > > > 
> > > 
> > > I don't use kas.
> > > 
> > > I've ran `bitbake -e multiconfig:qemuarm-stretch:isar-image-base` and
> > > DISTRO/DISTRO_SUITE are expanded properly:
> > > 
> > > # $DISTRO [2 operations]
> > > #   set /home/myo/work/isar/src/trunk/isar/build/conf/local.conf:30
> > > #     [_defaultval] "debian-stretch"
> > > #   set?
> > > /home/myo/work/isar/src/trunk/isar/meta-isar/conf/multiconfig/qemuarm-stretch.conf:6
> > > #     "debian-stretch"
> > > # pre-expansion value:
> > > #   "debian-stretch"
> > > DISTRO="debian-stretch"
> > > 
> > > ...
> > > 
> > > #
> > > # $DISTRO_SUITE
> > > #   set?
> > > /home/myo/work/isar/src/trunk/isar/meta/classes/base-apt-helper.bbclass:5
> > > #     "${@ d.getVar('DISTRO', True).split('-')[1]}"
> > > DISTRO_SUITE="stretch"
> > > 
> > > 
> > > 
> > > If I set in local.conf
> > > 
> > > DISTRO ??= "debian-jessie"
> > > 
> > > DISTRO/DISTRO_SUITE are also expanded properly:
> > > 
> > > # $DISTRO [2 operations]
> > > #   set /home/myo/work/isar/src/trunk/isar/build/conf/local.conf:30
> > > #     [_defaultval] "debian-jessie"
> > > #   set?
> > > /home/myo/work/isar/src/trunk/isar/meta-isar/conf/multiconfig/qemuarm-stretch.conf:6
> > > #     "debian-stretch"
> > > # pre-expansion value:
> > > #   "debian-stretch"
> > > DISTRO="debian-stretch"
> > > 
> > > ...
> > > 
> > > #
> > > # $DISTRO_SUITE
> > > #   set?
> > > /home/myo/work/isar/src/trunk/isar/meta/classes/base-apt-helper.bbclass:5
> > > #     "${@ d.getVar('DISTRO', True).split('-')[1]}"
> > > DISTRO_SUITE="stretch"
> > 
> > I did a little more testing.  Apparently, it works fine if the weak default value
> > contains at least one `-`.  The rest of the value can be anything (though I do get
> > some warnings if it is not a valid distro).
> > 
> > So this works:
> > 
> >      DISTRO ??= "invalid-distro"
> > 
> > But this doesn't:
> > 
> >      DISTRO ??= "invalid_distro"
> > 
> > 
> 
> I didn't dig into all details, and maybe this is actually resolving the issue 
> better, but I had to fix a similar issue with my kas-driven layer lik this: 
> https://github.com/siemens/jailhouse-images/commit/e595c6d62ddc6e8a608b199dc767dab9bc12f216

I am also able to reproduce this behavior with poky/sumo, so this is a bitbake issue and
not directly isar related.

I am unsure if it makes sense to follow up on this; this bug will only ever be triggered
if an invalid default value is provided, which is by itself a "bug" because a default
value that is supposed to be overwritten shouldn't be set in the first place ...

What do you think?

-- 
Harald

DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: +49-8142-66989-62  Fax: +49-8142-66989-80   Email: hws@denx.de