bug#21963: Spurious byte compile message: "Warning: the function `bar' might not be defined at runtime."

[Eli Zaretskii]

> Date: Fri, 20 Nov 2015 15:26:38 +0000
> Cc: 21963@debbugs.gnu.org
> From: Alan Mackenzie <acm@muc.de>
> 
> The first two lines of the file are:
> 
>    (eval-when-compile (require 'warning-bar))
>    (require 'warning-bar)

I think if you leave only the second one, Bob's your uncle.