Make pyinfo compatible with Python 2 (#12244)

hauntsaninja · web-flow · commit a3fc35a10dbf · 2022-02-22T19:44:27.000-08:00
I'm not adding a test because it's Python 2, but I did test locally.

Co-authored-by: hauntsaninja &lt;&gt;
diff --git a/mypy/pyinfo.py b/mypy/pyinfo.py
@@ -19,7 +19,7 @@
 
 def getprefixes():
     # type: () -> Tuple[str, str]
-    return sys.base_prefix, sys.prefix
+    return getattr(sys, "base_prefix", sys.prefix), sys.prefix
 
 
 def getsitepackages():
