Version 0.3.21 is available upstream. Please consider updating! It seems that version 0.3.21 is available upstream, while the latest version in the Gentoo tree is 0.3.19. You think this warning is false? Read more about it here.
Partial functions from the base library, such as @head@ and @!!@, modified
to return more descriptive error messages, programmer defined error messages,
@Maybe@ wrapped results and default values.
These functions can be used to reduce the number of unsafe pattern matches in
your code.