Merge branch 'main' into worktree-typed-sx

# Conflicts:
#	shared/sx/ref/platform_py.py
#	shared/sx/ref/sx_ref.py

shared/sx/types.py

@@ -376,6 +376,15 @@ class _ShiftSignal(BaseException):
         self.env = env
 
 
+# ---------------------------------------------------------------------------
+# EvalError
+# ---------------------------------------------------------------------------
+
+class EvalError(Exception):
+    """Error during expression evaluation."""
+    pass
+
+
 # ---------------------------------------------------------------------------
 # Type alias
 # ---------------------------------------------------------------------------