tlmgr in a Ubuntu-installed texlive

[Bob Tennent]

  BUT, tlmgr does NOT work out of the box on Debian/Ubuntu. Without any
  specific action from the user, it does nothing:

  $ tlmgr update --list
  (running on Debian, switching to user mode!)
  TLPDB: Cannot determine type of tlpdb from /home/norbert/texmf!
  tlmgr: running in usermode, did you call `tlmgr init-usertree'?
  $

  So a user needs to actively setting up user mode before it can work.

  A user who does this without reading the manual about tlmgr user mode
  is on their own.

This user *did*, as instructed, tlmgr init-usertree and was
happy for a while, but then ran into problems. Perhaps a
stern message about reading the manual (with a link to the
html version) is needed.

Bob T.