Symbol's function definition is void: locating the code

[Karl Voit]

Hi!

I sometimes face errors like this:

"avy-menu: Symbol's function definition is void:
with-current-buffer-window"

OK, so a package misses some function which is probably provided by
another package (missing dependency).

How do I locate the package which is able to provide me the
function?

Most of the time I get lucky by searching the web with the error
message. However, this time (and some other times), I am not able to
find the missing code.

-- 
All in all, one of the most disturbing things today is the definitive
fact that the NSA, GCHQ, and many more government organizations are
massively terrorizing the freedom of us and the next generations.
                                                  http://Karl-Voit.at