[oe] task-base dependencies and missing logging of failed providers

[Leon Woestenberg]

Hello,

just wanted to get this down for those not having followed the
discussion on IRC (and just for the record, not that the ideas are
still fresh).

My idea about a minimal image that OE should support (Goal: OE must be
scalable) is a linux kernel with a single init application
(helloworld).

Today on IRC we discussed two issues with BB/OE, indirectly blocking
the ability to build a minimal image using task-base, especially for
new users.

(1) task-base always wants *all* targets in task-* to be buildable,
regardless whether they are installed or not.

Example:

Take angstrom, strip {MACHINE,DISTRO}_FEATURES such that
COMBINED_FEATURES="ext2" or something really basic.
Set USE_NLS="no"

When now building angstrom-minimal-image, task-base wants bluetooth to
be buildable, thus bluez-utils, thus dbus, cups, glib-2.0, etc. etc.
Because glib-2.0 requires USE_NLS="yes", the image build fails with "a
no providers for" message.

[10:34]	<v8jlene>	likewise: Yeah, that task-base one's a bit annoying.
I only had about 400 recipes symlinked in, now I have them all just to
make task-base happy. And as you say it's building lots of stuff that
you don't use.

Workarounds:
- USE_NLS_glib-2.0="yes" (yes, at least makes image buildable, IFF the
other deps are met, everything is still built)

Suggested fixes:
- split task-base into seperate *.bb would work (koen, hrw), but this
is not the proper solution (RP, koen)
- do not use debian.bbclass (tried, but does not work for me)
- ...

(2) It's very hard to track down and I'm not alone:

[10:29]	<v8jlene>	likewise: Heh, I had that issue yesterday when
trying my uclibc builds with 1.8.2 ;) The error bitbake showed was
about bootstrap-image was unavailable (due to task-base pulling in
cups which pulled in dbus which pulled in glib-2.0). Took ages to
figure it all out...

New users won't find this, as bitbake -D -D -D -v does not provide this info.

2) bitbake will NOT report the above dependency
logging of failed providers

However, this one is hard to fix:

[10:31]	<RP>	likewise: There is a bitbake bug already open about the
logging of failed providers
[10:31]	<RP>	Its not as simple as it sounds though


Reproduce

taking the Ångström distro as a base, I would like to strip it down a
bit. I stripped {MACHINE,DISTRO}_FEATURES such that:

COMBINED_FEATURES="ext2"
DISTRO_EXTRA_RDEPENDS="update-modules module-init-tools
modutils-initscripts sysvinit initscripts sysvinit-pidof netbase
dropbear ipkg ipkg-collateral util-linux-mount util-linux-umount"

As none of the selected package need NLS, I have disabled it.

USE_NLS = "no"

bitbake angstrom-minimal image
or
bitbake bootstrap-image


Regards,
-- 
Leon

The persons and animals named in this email are based on true
characters in real life.