Patch urllib3 to mark the retry warning

src/pip/_internal/network/utils.py

@@ -159,21 +159,15 @@ def __init__(self, *, timeout: Optional[float], verbose: bool) -> None:
         self.verbose = verbose
 
     def filter(self, record: logging.LogRecord) -> bool:
-        # Attempt to "sniff out" the retrying warning.
-        if not isinstance(record.args, tuple):
+        # We patch urllib3 to include an extra attribute on the retrying warning
+        # that we want to rewrite.
+        context = getattr(record, "pip_urllib3_retry_warning", None)
+        if context is None:
             return True
 
-        retry = next(
-            (a for a in record.args if isinstance(a, urllib3.util.Retry)), None
-        )
-        if record.levelno != logging.WARNING or retry is None:
-            # Not the right warning, leave it alone.
-            return True
-
-        error = next((a for a in record.args if isinstance(a, Exception)), None)
-        if error is None:
-            # No error information available, leave it alone.
-            return True
+        retry, error = context
+        assert isinstance(retry, urllib3.util.Retry)
+        assert isinstance(error, Exception)
 
         rewritten = False
         if isinstance(error, urllib3.exceptions.NewConnectionError):

src/pip/_vendor/urllib3/connectionpool.py

@@ -822,7 +822,8 @@ def _is_ssl_error_message_from_http_proxy(ssl_error):
         if not conn:
             # Try again
             log.warning(
-                "Retrying (%r) after connection broken by '%r': %s", retries, err, url
+                "Retrying (%r) after connection broken by '%r': %s", retries, err, url,
+                extra={"pip_urllib3_retry_warning": (retries, err)}
             )
             return self.urlopen(
                 method,

tools/vendoring/patches/urllib3-retry-warning.patch

@@ -0,0 +1,14 @@
+diff --git a/src/pip/_vendor/urllib3/connectionpool.py b/src/pip/_vendor/urllib3/connectionpool.py
+index 5a6adcbdc..b973d287d 100644
+--- a/src/pip/_vendor/urllib3/connectionpool.py
++++ b/src/pip/_vendor/urllib3/connectionpool.py
+@@ -822,7 +822,8 @@ class HTTPConnectionPool(ConnectionPool, RequestMethods):
+         if not conn:
+             # Try again
+             log.warning(
+-                "Retrying (%r) after connection broken by '%r': %s", retries, err, url
++                "Retrying (%r) after connection broken by '%r': %s", retries, err, url,
++                extra={"pip_urllib3_retry_warning": (retries, err)}
+             )
+             return self.urlopen(
+                 method,