Tramp shows no user/host completions (solved while writing)

[Tassilo Horn]

Hi all,

with "emacs -q", C-x C-f /ssh:<tab> showed many completions for host
names but with my custom emacs setup, it just says [no matches].  I've
debugged around for an hour, started to write this mail, and then
eventually found the culprit.

It seems like you absolutely must have the `basic' completion style in
`completion-styles' or the `file' entry in
`completion-category-overrides'.  No `basic', no Tramp username/hostname
completions.

Just in case someone runs into the same issue...

Bye,
Tassilo