It's powerful but bitbake wasn't so much designed as emerged from a primordial soup, it's easy to go completely insane trying to debug it due to the amount of action-at-distance recipes and layers can create. (try playing the "where did this compile flag come from?" game)
I don't disagree, but wanted to note- if you're ever stuck trying to trace a value, you can see everything that went into its calculation by using "bitbake -e".
bitbake -e <recipe> is super useful for that game. It dumps out a complete history of where all variables were set/changed, and their values along the way. I also use it to do what I call "variable shopping," where I roughly know what path/name content I need, but not what the variable it is in is called.
