[oe] meta-toolchain-qt5, qttools-plugins and -nomake examples

[Ivan Sergio Borgonovo]

I think I've been able to find all and only the packages that should be 
conditionally added to RDEPENDS in packagegroup-qt5-toolchain-target.bb 
from opengl.

I finally discovered why there was a problem with meta-toolchain-qt5 and 
qttools-plugins... qttools-plugins doesn't get build when

-nomake examples

Now I don't understand:
- why nobody noticed this problem that doesn't seem related to opengl or 
x11. Was it hidden by something else that I should take care when trying 
to fix it? No one is actually baking meta-toolchain-qt5?...

- what should be considered a correct solution:
* simply remove the package that doesn't really seem that useful in a 
toolchain (they should be example plugins for qtcreator)
* conditionally add it just if qt get build with examples [1]
* still adding qttools-plugins in local.conf will trigger the problem. 
Is there a way to automatically enable a "package feature" if a package 
get included?
One of the way to "fix" this could be to
PACKAGECONFIG_DISTRO_append_pn-qtbase = " examples..."

What is the consensus so I could adapt my patch to
packagegroup-qt5-toolchain-target.bb
and get a chance to see it merged?

thanks

[1] How? I know how to check if a DISTRO_FEATURES has been enabled but 
how can I check if a package option has been enabled?
-- 
Ivan Sergio Borgonovo
http://www.webthatworks.it