Logos.MacroError exception (Logos v0.2.0)

Raised when applying a macro (during Logos.Macroexpand.expand/3) fails -- e.g. the macro function itself errors, or is called with a mismatched arity. Macroexpansion has no {:error, _}-tuple convention of its own (see Logos.Macroexpand's moduledoc), so failures here are surfaced as a real exception, the same way a reader syntax error would be.