-- main.mcl --
$st = struct{
	a => 42,
	b => true,
	c => "wow",
}

# Since there is no field named "missing", we can't guess what the zero value
# would be for this field, and as a result, we can't unify or compile this code!
$name = $st->missing + "fail"
test "${name}" {} # this can't unify!
-- OUTPUT --
# err: errUnify: error setting type: func() { <built-in:_struct_lookup> }, error: field missing was not found in struct
