In Emacs, what does this error mean? "Warning: cl package required at runtime"

Question

I am byte-compiling a module. It gives me this warning:

 Warning: cl package required at runtime 

Why is this a warning? I am well aware that I am using the cl package. In fact there is a (require 'cl) statement in the module.

Is there something wrong with using the cl stuff?

If so, is there a list of published workarounds? The main things I use are mapcan and delete-duplicates.

Answer 1

The reason of this warning is a GNU policy which does not want a package cl to be used in Elisp. But it would be foolish as well to prohibit it completely. So they decided to show a warning.

You can find more information here