From 34a82968597ea581b3f251aa9147a8e6e438fda3 Mon Sep 17 00:00:00 2001
From: Adam Turner <9087854+AA-Turner@users.noreply.github.com>
Date: Tue, 31 May 2022 18:37:28 +0100
Subject: [PATCH] Add a warning

---
 sphinx/builders/gettext.py | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/sphinx/builders/gettext.py b/sphinx/builders/gettext.py
index 0f38ea7f5..4aa3cf5d4 100644
--- a/sphinx/builders/gettext.py
+++ b/sphinx/builders/gettext.py
@@ -53,11 +53,15 @@ class Catalog:
         if msg not in self.metadata:  # faster lookup in hash
             self.messages.append(msg)
             self.metadata[msg] = []
-        self.metadata[msg].append((origin.source, origin.line, origin.uid))  # type: ignore
+        line = origin.line
+        if line is None:
+            logger.warning(f"Node {origin!r} has no line number, using '-1'.")
+            line = -1
+        self.metadata[msg].append((origin.source, line, origin.uid))  # type: ignore
 
     def __iter__(self) -> Generator[Message, None, None]:
         for message in self.messages:
-            positions = sorted(set((source, line or -1) for source, line, uuid
+            positions = sorted(set((source, line) for source, line, uuid
                                    in self.metadata[message]))
             uuids = [uuid for source, line, uuid in self.metadata[message]]
             yield Message(message, positions, uuids)