only do this sys.stderr replacing on CPython
diff --git a/Lib/lib2to3/pytree.py b/Lib/lib2to3/pytree.py
index b24283e..c2fa800 100644
--- a/Lib/lib2to3/pytree.py
+++ b/Lib/lib2to3/pytree.py
@@ -743,9 +743,11 @@
else:
# The reason for this is that hitting the recursion limit usually
# results in some ugly messages about how RuntimeErrors are being
- # ignored.
- save_stderr = sys.stderr
- sys.stderr = StringIO()
+ # ignored. We don't do this on non-CPython implementation because
+ # they don't have this problem.
+ if hasattr(sys, "getrefcount"):
+ save_stderr = sys.stderr
+ sys.stderr = StringIO()
try:
for count, r in self._recursive_matches(nodes, 0):
if self.name:
@@ -759,7 +761,8 @@
r[self.name] = nodes[:count]
yield count, r
finally:
- sys.stderr = save_stderr
+ if hasattr(sys, "getrefcount"):
+ sys.stderr = save_stderr
def _iterative_matches(self, nodes):
"""Helper to iteratively yield the matches."""