Fix the double inclusion of parsed DZN files

Author: Dekker1

CHANGELOG.rst

@@ -21,6 +21,7 @@ Fixed
 ^^^^^
 - Catch lark ``ImportError`` before ``LarkError`` during ``Model.add_file()`` since
   ``LarkError`` will not exist if the import failed.
+- Ensure a DZN file does not get included if its data is parsed.
 
 0.3.3_ - 2020-08-17
 -------------------

src/minizinc/model.py

@@ -182,9 +182,9 @@ def add_file(self, file: ParPath, parse_data: bool = True) -> None:
                         f"Could not parse {file}. Parameters included within this file "
                         f"are not available in Python"
                     )
+                    with self._lock:
+                        self._includes.append(file)
             except ImportError:
-                pass
-            finally:
                 with self._lock:
                     self._includes.append(file)
         elif file.suffix not in [".dzn", ".mzn", ".mzc"]: