From 5fe6a62aaafbd8f970dbcf95aa6344c4b784a68e Mon Sep 17 00:00:00 2001
From: Dustin Spicuzza <dustin@virtualroadside.com>
Date: Mon, 15 Feb 2021 00:16:58 -0500
Subject: [PATCH] Sometimes _viewcode_modules can be False; don't crash when it
 is

- Fixes #8880
---
 sphinx/ext/viewcode.py | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/sphinx/ext/viewcode.py b/sphinx/ext/viewcode.py
index 21cff6a032a..6bedf2e1c5b 100644
--- a/sphinx/ext/viewcode.py
+++ b/sphinx/ext/viewcode.py
@@ -152,7 +152,11 @@ def env_merge_info(app: Sphinx, env: BuildEnvironment, docnames: Iterable[str],
 def env_purge_doc(app: Sphinx, env: BuildEnvironment, docname: str) -> None:
     modules = getattr(env, '_viewcode_modules', {})
 
-    for modname, (code, tags, used, refname) in list(modules.items()):
+    for modname, entry in list(modules.items()):
+        if entry is False:
+            continue
+
+        code, tags, used, refname = entry
         for fullname in list(used):
             if used[fullname] == docname:
                 used.pop(fullname)