Handle rg execution failures in memory search

engine/antigravity_engine/tools/memory_tools.py

@@ -92,8 +92,8 @@ def search_memory_md(
             return completed.stdout.strip()
         if completed.returncode in (0, 1):
             return "No matching memory lines found."
-    except FileNotFoundError:
-        # Fallback for environments without ripgrep installed.
+    except OSError:
+        # Fallback for environments where ripgrep is missing or cannot run.
         pass
 
     matches = []

engine/tests/test_memory_tools.py

@@ -27,6 +27,30 @@ def test_search_memory_md(tmp_path):
     assert "microsandbox" in result.lower()
 
 
+def test_search_memory_md_falls_back_when_rg_cannot_run(tmp_path, monkeypatch):
+    memory_file = tmp_path / "agent_memory.md"
+    memory_file.write_text(
+        "# Agent Memory Log\n\nMicrosandbox enabled.\nDocker removed.\n",
+        encoding="utf-8",
+    )
+
+    def raise_permission_error(*args, **kwargs):
+        raise PermissionError("rg is not executable")
+
+    monkeypatch.setattr(
+        "antigravity_engine.tools.memory_tools.subprocess.run",
+        raise_permission_error,
+    )
+
+    result = search_memory_md(
+        query="docker",
+        max_results=5,
+        memory_file=str(memory_file),
+    )
+
+    assert "Docker removed." in result
+
+
 def test_search_memory_md_empty_query(tmp_path):
     memory_file = tmp_path / "agent_memory.md"
     memory_file.write_text("any", encoding="utf-8")