Oh yeah, warnings really don’t make any sense (and errors even less).

The only sensible option is ignoring.

Ignoring + always recompiling doesn’t really make sense. If we let nanoc always recompile anything that depends on an external file, then *everything* will always be recompiled, because there’s plenty of dependencies on Ruby source code, external libraries, OS functionality, etc… so always recompiling is not a sensible option.