How do I solve this kind of conflict?

[Marc]

I was using a Sqlite3 library then I included another library 
that started the conflict. From what I could tell, it seems it's 
another Sqlite3 engine that the included library uses. The link 
error is:

>.dub\build\application-debug-windows-x86-dmd_2076-E7D07B7BDA58325E30A3C637FC043AFE\foo.obj(ytdl)  Offset BA31FH Record Type 00C3
> Error 1: Previous Definition Different : _callback
> Error: linker exited with status 1

My guess is it's symbols visibility issue? and how can I solve 
this?

But libraries has this defined:

> extern(C) int callback(void*, int, char** , char**){

I've trid mark the one without private as such but it didn't 
change anything.

NOTE: Albeit I'm using dub, both those libraries were included 
directly (except the dependences of one of them).