Frank Terbeck <ft@bewatermyfriend.org>:
[...]
> check_com() *would* be available for completions, too. I mean, in what
[...]

Wrong wrong wrong wrong...
check_com() is currently *not* available outside of our zshrc.
This has nothing to do with the (non-)interactive state of the shell,
though. We are unfunctioning the function definition after the zshrc
is sourced.

Regards, Frank