cubicweb #2981477 upgrading to 3.17 [validation pending]

After upgrading CubicWeb packages from 3.16.4 to 3.17.2 on our Ubuntu 12.04 server, I had to manually install the following cubes to be able to upgrade the databases:
* cubicweb-sioc
* cubicweb-embed
* cubicweb-geocoding

This might be expected if I read "What's new in CubicWeb 3.17" correctly. However may I suggest you specifically document it?

With the above cubes missing, the error message is:

$ cubicweb-ctl upgrade imagen

Upgrading the instance imagen
-----------------------------
/var/run/cubicweb/imagen-all-in-one.pid doesn't exist.
-> migration needed from 3.16.4 to 3.17.2 for cubicweb
Backup imagen database? [Y/n/a(bort)/s(hell)]: n
-> no backup done.
Execute '/usr/share/cubicweb/migration/bootstrapmigration_repository.py' ? [Y/n/s(how)/a(bort)]:
Execute command: add_cube('sioc', update_database=False) ? [Y/n/a(bort)/s(hell)]:
instance imagen not upgraded: unable to find packaging information for cube sioc (ImportError: No module named sioc.__pkginfo__)
$

priorityimportant
typebug
done in3.17.4
load1.000
load left0.000
closed by#fe4c1c1982e7 [3.17 migration] when some cube is missing, add_cube raise ConfigurationError, not ImportError. Closes #2981477
patch[migration] when adding a cube, skip infered relations (they will be recalculated later). Closes #2981477 [applied][3.17 migration] when some cube is missing, add_cube raise ConfigurationError, not ImportError. Closes #2981477 [applied]