Add traceback info for visit_block

trans/transpiler/phases/typing/common.py

@@ -2,6 +2,7 @@ import ast
 from dataclasses import dataclass, field
 from typing import Dict, Optional
 
+from transpiler.utils import highlight
 from transpiler.phases.typing.annotations import TypeAnnotationVisitor
 from transpiler.phases.typing.scope import Scope, ScopeKind, VarDecl
 from transpiler.phases.typing.types import BaseType, TypeVariable, TY_NONE, TypeType
@@ -24,6 +25,9 @@ class ScoperVisitor(NodeVisitorSeq):
         return res
 
     def visit_block(self, block: list[ast.AST]):
+        if not block:
+            return
+        TB = f"running type analysis on block starting with {highlight(block[0])}"
         from transpiler.phases.typing.block import ScoperBlockVisitor
         self.fdecls = []
         for b in block: