Fix test_regrtest (hopefully)

Lib/test/libregrtest/refleak.py

@@ -48,11 +48,13 @@ def dash_R(ns, test_name, test_func):
     else:
         zdc = zipimport._zip_directory_cache.copy()
     abcs = {}
-    for abc in [getattr(collections.abc, a) for a in collections.abc.__all__]:
-        if not isabstract(abc):
-            continue
-        for obj in abc.__subclasses__() + [abc]:
-            abcs[obj] = _get_dump(obj)[0]
+    # catch and ignore collections.abc.ByteString deprecation
+    with warnings.catch_warnings(action='ignore', category=DeprecationWarning):
+        for abc in [getattr(collections.abc, a) for a in collections.abc.__all__]:
+            if not isabstract(abc):
+                continue
+            for obj in abc.__subclasses__() + [abc]:
+                abcs[obj] = _get_dump(obj)[0]
 
     # bpo-31217: Integer pool to get a single integer object for the same
     # value. The pool is used to prevent false alarm when checking for memory
@@ -173,7 +175,9 @@ def dash_R_cleanup(fs, ps, pic, zdc, abcs):
         zipimport._zip_directory_cache.update(zdc)
 
     # Clear ABC registries, restoring previously saved ABC registries.
-    abs_classes = [getattr(collections.abc, a) for a in collections.abc.__all__]
+    # ignore deprecation warning for collections.abc.ByteString
+    with warnings.catch_warnings(action='ignore', category=DeprecationWarning):
+        abs_classes = [getattr(collections.abc, a) for a in collections.abc.__all__]
     abs_classes = filter(isabstract, abs_classes)
     for abc in abs_classes:
         for obj in abc.__subclasses__() + [abc]: