[oe] Hidden depenencies

[Thomas Kunze]

Hi everybody,

I just spend some hours to figure out why a kernel module I added to
MACHINE_EXTRA_RRECOMMENDS didn't show up in images. The solution is to
rebuild task-base. I think there should a way to handle this in oe. But
for now we should document such hidden dependencies. Where should this
be in the wiki? Do you know additional hidden dependencies?

My list so far:
MACHINE_EXTRA_RRECOMMENDS -> task-base
module_autoload_* -> virtual/kernel

Regards,
Thomas