From e746df0297b4c71b6e7b24bb9df44cba3dc20559 Mon Sep 17 00:00:00 2001
From: Adrian Chaves <adrian@zyte.com>
Date: Fri, 19 Jun 2026 17:31:10 +0200
Subject: [PATCH] Add a comment about the content of self._last_backout

---
 scrapy/core/downloader/__init__.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/scrapy/core/downloader/__init__.py b/scrapy/core/downloader/__init__.py
index 50ccba7d3..d0239414d 100644
--- a/scrapy/core/downloader/__init__.py
+++ b/scrapy/core/downloader/__init__.py
@@ -134,6 +134,8 @@ class Downloader:
             "DOWNLOAD_SLOTS"
         )
         self._stats = crawler.stats
+        # (reason, start_time): current backout reason and when it began, or
+        # (None, None) if not backing out.
         self._last_backout: tuple[str | None, float | None] = (None, None)
 
         deprecated_setting_priority = self.settings.getpriority(