...

compiler/NubLang.CLI/Program.cs

@@ -21,7 +21,7 @@ foreach (var file in args)
 }
 
 var modules = Module.Collect(syntaxTrees);
-var compilationUnits = new List<CompilationUnit>();
+var compilationUnits = new List<CompilationUnit?>();
 
 for (var i = 0; i < args.Length; i++)
 {
@@ -51,6 +51,11 @@ for (var i = 0; i < args.Length; i++)
     var file = args[i];
     var compilationUnit = compilationUnits[i];
 
+    if (compilationUnit == null)
+    {
+        continue;
+    }
+
     var generator = new Generator(compilationUnit);
     var directory = Path.GetDirectoryName(file);
     if (!string.IsNullOrWhiteSpace(directory))