[python] PY-84883 allow debugging modules with Python 3.14

- `pkgutil.get_loader()` was removed in Python 3.14
- switch to `importlib.util.find_spec()` instead


(cherry picked from commit 688119f9a207eb2c204ddb89ac0770ab3d800956)

IJ-MR-178861

GitOrigin-RevId: 7849bfab553c88318ee353f38c2b33224c5f4cb2

python/helpers/pydev/pydevd_file_utils.py

@@ -611,19 +611,25 @@ def get_abs_path_real_path_and_base_from_frame(frame):
 
 
 def get_fullname(mod_name):
-    if IS_PY3K:
-        import pkgutil
-    else:
-        from _pydev_imps import _pydev_pkgutil_old as pkgutil
     try:
+        import importlib.util
+
+        spec = importlib.util.find_spec(mod_name)
+        if spec is not None and spec.origin is not None:
+            return spec.origin
+    except ImportError:
+        pass
+
+    if not IS_PY3K:
+        from _pydev_imps import _pydev_pkgutil_old as pkgutil
+
         loader = pkgutil.get_loader(mod_name)
-    except:
-        return None
-    if loader is not None:
-        for attr in ("get_filename", "_get_filename"):
-            meth = getattr(loader, attr, None)
-            if meth is not None:
-                return meth(mod_name)
+        if loader is not None:
+            for attr in ("get_filename", "_get_filename"):
+                meth = getattr(loader, attr, None)
+                if meth is not None:
+                    return meth(mod_name)
+
     return None
 
 

python/helpers/pydev/tests/test_pydevd_file_utils.py

@@ -0,0 +1,9 @@
+from pydevd_file_utils import get_fullname
+
+
+def test_get_fullname_exists():
+    assert get_fullname('pydevd_file_utils').endswith('pydevd_file_utils.py')
+
+
+def test_get_fullname_unknown():
+    assert get_fullname("hello_world") is None