Emacs: Warning (bytecomp): reference to free variable ‘log4slime-mode’

[hww]

Ruunig Emacs-25.3.1 display this warning:
Warning (bytecomp): reference to free variable ‘log4slime-mode’

[MartinBuchmann]

I am still seeing this issue with Emacs 26. I simply added (defvar log4slime-mode t) to my init.el before loading log4slime-setup.el and it stops the warning at least. I have little knowledge of emacs lisp and am not sure if setting the variable to tmakes sense but it seems to work for me.