The function `slime-c-p-c-init' in `contrib/slime-c-p-c.el' defines a keybinding for `slime-complete-form' (binding it to `C-c C-s') in the `slime-mode-map'.
Unfortunately this keybinding (and actually any keybinding defined in a contrib, I think) cannot possibly propagate to the REPL, or rather `slime-repl-mode-map', because of how that keymap is currently being contrived.
How should contribs define keybindings that are also valid on the REPL? Define the same keybinding in `slime-mode-map', _and_ `slime-repl-mode-map' explicitly?
-T.