fix(opendss): restore OpenDSSDirect.py as a dev dependency

CHANGELOG.rst

@@ -3,6 +3,7 @@ Change Log
 
 [upcoming release] - 2026-..-..
 -------------------------------
+- [FIXED] restored ``OpenDSSDirect.py`` to the ``all``/``dev`` extras so the OpenDSS converter is exercised (and its coverage reported) in CI again; it was dropped in #3062 because installing it alongside ``pytest~=9.1`` crashed the pytest process on Windows. Root cause (see `dss-extensions/OpenDSSDirect.py#148 <https://github.com/dss-extensions/OpenDSSDirect.py/issues/148>`_): pytest enables Python's ``faulthandler`` by default, which intercepts a first-chance Windows structured exception that OpenDSSDirect.py's native backend raises -- and normally handles itself -- during import, and misreports it as fatal. Bracketing the import with ``faulthandler.disable()``/``.enable()`` avoids the false crash while leaving ``faulthandler`` protecting the rest of the test run; the converter now runs on Windows instead of merely skipping there.
 - [ADDED] OpenDSS converter: series (bus-to-bus) ``Reactor`` elements are now imported as a fixed-impedance ``line``, the pattern some feeder libraries (e.g. EPRI's Ckt5/Ckt7) use to model the substation's Thevenin-equivalent source impedance instead of a ``Transformer``.
 
 [3.5.4] - 2026-07-08

pandapower/converter/opendss/from_dss.py

@@ -19,6 +19,7 @@
 # The circuit is read through the ``OpenDSSDirect.py`` API (lazy-imported), not a
 # text parser, so every OpenDSS-supported master file is understood.
 
+import faulthandler
 import logging
 import math
 from dataclasses import dataclass, field
@@ -28,7 +29,22 @@
 import pandapower as pp
 
 try:
-    import opendssdirect as dss
+    # On Windows, OpenDSSDirect.py's native backend (dss_python_backend) raises an
+    # internal, first-chance structured exception during its own startup -- one its
+    # Free Pascal runtime normally handles and silences itself. If a Windows crash
+    # handler is already installed (as Python's faulthandler does, and pytest enables
+    # faulthandler by default), it intercepts that exception first and misreports it
+    # as fatal, killing the whole process instead of a clean ImportError. Disable
+    # faulthandler for just this import, then restore it -- it's still needed to
+    # catch genuine crashes elsewhere. See
+    # https://github.com/dss-extensions/OpenDSSDirect.py/issues/148
+    faulthandler_was_enabled = faulthandler.is_enabled()
+    faulthandler.disable()
+    try:
+        import opendssdirect as dss
+    finally:
+        if faulthandler_was_enabled:
+            faulthandler.enable()
 
     opendssdirect_imported = True
 except ImportError:

pandapower/test/converter/test_from_opendss.py

@@ -12,13 +12,27 @@
 import promises for symmetric feeders.
 """
 
+import faulthandler
+
 import numpy as np
 import pytest
 
 import pandapower as pp
 
-# OpenDSSDirect.py is an optional dependency; skip the whole module without it.
-pytest.importorskip("opendssdirect")
+# pytest enables faulthandler by default, which on Windows intercepts a first-chance
+# structured exception that OpenDSSDirect.py's native backend raises (and normally
+# handles itself) during import -- see pandapower/converter/opendss/from_dss.py for
+# the full explanation and https://github.com/dss-extensions/OpenDSSDirect.py/issues/148.
+# Disable faulthandler for this pre-flight import check the same way, so it doesn't
+# crash here before from_dss's own guarded import ever runs.
+faulthandler_was_enabled = faulthandler.is_enabled()
+faulthandler.disable()
+try:
+    # OpenDSSDirect.py is an optional dependency; skip the whole module without it.
+    pytest.importorskip("opendssdirect")
+finally:
+    if faulthandler_was_enabled:
+        faulthandler.enable()
 
 from pandapower.converter.opendss import from_opendss
 

pyproject.toml

@@ -106,7 +106,7 @@ typing = [
 ]
 
 #all = ["pandapower[plotting,performance,fileio,converter,pgm,control,helm,opendss]"]
-all = ["pandapower[plotting,performance,fileio,converter,pgm,control]"]
+all = ["pandapower[plotting,performance,fileio,converter,pgm,control,opendss]"]
 dev = ["pandapower[all,docs,test,typing,pandamodels,tutorials]"]
 # "shapely", "pyproj", "Pyogrio" are dependencies of geopandas and should be already available ("Fiona" got dropped)
 # "hashlib", "zlib", "base64" produce install problems, so they are not included