diff --git a/guix-data-service/model/git-repository.scm b/guix-data-service/model/git-repository.scm
index 0e6327c..8efedcd 100644
--- a/guix-data-service/model/git-repository.scm
+++ b/guix-data-service/model/git-repository.scm
@@ -150,6 +150,10 @@ WHERE id = $1"
 
           (for-each
            (lambda (repo)
+             (simple-format (current-error-port)
+                            "specifying fields for repository ~A: ~A\n"
+                            (assq-ref repo 'id)
+                            (map car repo))
              (let ((fields (map car repo))
                    (field-vals (map cdr repo)))
                (update-or-insert