harded the link checker

conftest.py

@@ -1,17 +1,57 @@
 import os
+import time
+from functools import wraps
+
 import requests
 
 
+def _get_env_number(name, default, cast):
+    value = os.environ.get(name)
+    if value is None:
+        return default
+
+    try:
+        return cast(value)
+    except ValueError:
+        return default
+
+
 def pytest_configure(config):
     if not getattr(config.option, "check_links", False):
         return
 
-    timeout = float(os.environ.get("CHECK_LINKS_TIMEOUT", "10"))
-    original_request = requests.sessions.Session.request
+    timeout = _get_env_number("CHECK_LINKS_TIMEOUT", 10.0, float)
+    max_retries = max(0, _get_env_number("CHECK_LINKS_RETRIES", 2, int))
+    retry_backoff = max(0.0, _get_env_number("CHECK_LINKS_RETRY_BACKOFF", 1.0, float))
+    current_request = requests.sessions.Session.request
 
+    if getattr(current_request, "_check_links_wrapped", False):
+        return
+
+    retryable_methods = {"GET", "HEAD"}
+    retryable_errors = (
+        requests.exceptions.Timeout,
+        requests.exceptions.ConnectionError,
+    )
+
+    @wraps(current_request)
     def request_with_timeout(self, method, url, **kwargs):
         if kwargs.get("timeout") is None:
             kwargs["timeout"] = timeout
-        return original_request(self, method, url, **kwargs)
 
+        method_name = (method or "").upper()
+
+        for attempt in range(max_retries + 1):
+            try:
+                return current_request(self, method, url, **kwargs)
+            except retryable_errors:
+                should_retry = method_name in retryable_methods and attempt < max_retries
+                if not should_retry:
+                    raise
+
+                # Retries smooth over transient CI/network blips without masking real 4xx/5xx failures.
+                if retry_backoff:
+                    time.sleep(retry_backoff * (attempt + 1))
+
+    request_with_timeout._check_links_wrapped = True
     requests.sessions.Session.request = request_with_timeout