Just configure the custom option icicle-completion-key-bindings :
Mx customize-option icicle-completion-key-bindings
By default, this parameter value contains a space character binding (printed as SPC , but is used as " " in the key binding) for the icicle-self-insert command --- delete this binding record. You can also add a binding for the space key to the icicle-word-completion-keys option, if you wish.
However, my advice is to leave the SPC as a self-tuning character (similarly ? ). Even vanilla Emacs started creating char spaces for self-insertion, at least for file names ...
source share