[yocto] meta-toolchain-sdk fails in edison with package_ipk

[Andrea Galbusera]

Hello,
Is there any known problem when building meta-toolchain-sdk target
with PACKAGE_CLASSES = "package_ipk" ?

I have deterministic failure in do_populate_sdk with latest edison
metadata and default local.conf (other than changing PACKAGE_CLASSES
to ipk).
Don't have a denzil tree at hand, but I'm going to check if this is
reproducible with 1.2 too.

To me it seem the failing task is trying to access host files on my
build system. Here is the first error I can see:

> Installing libtelepathy-dbg (0.3.3-r3) to root...
> Downloading file:/scratch/gizero/edison-build-raid.orig/tmp/deploy/ipk/i586/libtelepathy-dbg_0.3.3-r3_i586.ipk.
> touch: cannot touch `/etc/shells': Permission denied
> mkdir: cannot create directory `/var/lib/opkg/alternatives': Permission denied

Here you can see the full log (few lines stripped to satisfy pastebin
size limits...):

http://pastebin.com/Gim3DacX

Build works when I switch to rpm instead of ipk, but I want ipk for my
target and, at moment, I need to switch back and forth the two formats
when I need to update either my images or my sdk. Is there a smarter
way to stay with rpm for the sdk and with ipk for the target images?

Andrea