It might be ok in some context (we want to be stricter)

If builtin is non-exec, and deep-cover was executed, then return non-exec.

Probable replacement for `#executable?`

Instead of receiving the children from the initializer, use default argment so that when base_nod...

Used by error messages

Things a much clearer with caller doing the default manually using either || or return if.

Simpler error messages code

Removes some code smells