bug 439967: A call to compiler.ast_to_src crashes

metalua/compiler.lua

diff --git a/metalua/compiler.lua b/metalua/compiler.lua
index 202b254..9b0e56b 100644
--- a/metalua/compiler.lua
+++ b/metalua/compiler.lua
@@ -166,7 +166,7 @@
 
 function CONV :ast_to_src(...)
 	require 'metalua.loader' -- ast_to_string isn't written in plain lua
-	return require 'metalua.compiler.ast_to_src' (...)
+	return require 'metalua.compiler.ast_to_src'.new()(...)
 end
 
 local MT = { __index=CONV, __type='metalua.compiler' }