Hi,

project--keymap-prompt searches project-prefix-map *plus* the global
keymap when constructing the prompt for project-switch-command.  This
can result in weird behavior; for example,

    (global-set-key (kbd "M-s r") 'rgrep)
    (require 'project)
    (define-key project-prefix-map (kbd "<f5>") 'rgrep)
    (push '(rgrep "rgrep") project-switch-commands)

might (or will?) cause project-switch-project to display "[M-s r] rgrep"
instead of the expected "[<f5>] rgrep".

The attached patch fixes the issue as per the documentation of
`where-is-internal'.

Best regards,
Dario