This is mostly a note to myself... After setting up a minimal Ubuntu server install (in Xen), following these instructions using debootstrap I saw lots of errors like this:
perl: warning: Setting locale failed. perl: warning: Please check that your locale settings: LANGUAGE = (unset), LC_ALL = (unset), LANG = "en_US.UTF-8" are supported and installed on your system. perl: warning: Falling back to the standard locale ("C").
locale -a would show
While a full Ubuntu server install (off a CD) would show:
C en_US.utf8 POSIX
This command seems to have generated the missing locale and made everybody happy.
localedef --no-archive -i en_US -c -f UTF-8 en_US.UTF-8