cubicweb #1808195 ImportError: No module named cubicweb.cwctl under Natty [deprecated]

Under ubuntu natty, with an installation from /acceptance, I get

$ cubicweb-ctl
Traceback (most recent call last):
  File "/usr/bin/cubicweb-ctl", line 2, in <module>
    from cubicweb.cwctl import run
ImportError: No module named cubicweb.cwctl
prioritynormal
typebug
done in<not specified>
load0.000
load left0.000
closed by<not specified>