fix(tools): StubProbe missing capabilities property breaks pyocd list --targets --pack=... (closes #1959)

pyocd/tools/lists.py

@@ -33,6 +33,17 @@ class StubProbe(DebugProbe):
     def unique_id(self) -> str:
         return "0"
 
+    @property
+    def capabilities(self):
+        # `DebugProbe.capabilities` is abstract (raises NotImplementedError),
+        # so any caller that touches this property on a StubProbe — including
+        # `ListGenerator.list_targets()` when a CMSIS-Pack file is passed via
+        # `pyocd list --targets --pack=...` — crashes before producing any
+        # output. The stub has no real probe capabilities; return an empty
+        # set so the consuming code paths simply see "this probe supports
+        # nothing" and move on (issue #1959).
+        return set()
+
 class ListGenerator(object):
     @staticmethod
     def list_probes():

test/unit/test_stub_probe.py

@@ -0,0 +1,40 @@
+# pyOCD debugger
+# Copyright (c) 2026 pyOCD contributors
+# SPDX-License-Identifier: Apache-2.0
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+
+"""Regression tests for `pyocd.tools.lists.StubProbe`."""
+
+from pyocd.tools.lists import StubProbe
+
+
+def test_stub_probe_unique_id_is_string():
+    """`StubProbe` is used as a placeholder when no real probe is needed
+    (e.g. by `ListGenerator.list_targets()` when called with a CMSIS-Pack
+    file). It must satisfy the abstract members of `DebugProbe` that
+    consumers touch on the stub."""
+    assert StubProbe().unique_id == "0"
+
+
+def test_stub_probe_capabilities_returns_empty_set():
+    """Regression for #1959.
+
+    `DebugProbe.capabilities` is abstract — accessing it on a class that
+    does not override it raises `NotImplementedError`. Before this fix,
+    `StubProbe` did not override it, so `pyocd list --targets
+    --pack=<file>` failed silently the moment any code path queried the
+    stub's capabilities. An empty set is the correct stub value: it
+    truthfully reports that this placeholder has no real probe features.
+    """
+    caps = StubProbe().capabilities
+    assert caps == set()
+    # The set must be iterable and membership-testable so downstream
+    # `Capability.X in probe.capabilities` checks behave as if the probe
+    # simply lacks every feature, rather than crashing.
+    assert hasattr(caps, "__iter__")
+    assert hasattr(caps, "__contains__")