From f7b823cfd951f7832412832db05fd5419645f90e Mon Sep 17 00:00:00 2001
From: Christopher Baines <mail@cbaines.net>
Date: Fri, 9 Jun 2023 16:23:35 +0100
Subject: [PATCH] Fix fetch-narinfo-files to work in the specific outputs case

---
 guix-data-service/substitutes.scm | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/guix-data-service/substitutes.scm b/guix-data-service/substitutes.scm
index 24b141d..54b4c9e 100644
--- a/guix-data-service/substitutes.scm
+++ b/guix-data-service/substitutes.scm
@@ -132,9 +132,10 @@
                   build-server-id
                   filtered-narinfos)))))
 
-          (loop (second (last outputs-chunk))
-                total-requested
-                total-narinfos))))))
+          (unless specific-outputs
+            (loop (false-if-exception (second (last outputs-chunk)))
+                  total-requested
+                  total-narinfos)))))))
 
 (define %substitute-query-channel #f)