From db3d440e2664e8aaf67742b6fd545cf148fe5016 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Na=C3=AFm=20Favier?= <n@monade.li>
Date: Sun, 14 May 2023 12:05:10 +0200
Subject: [PATCH] kitty: improve error message when theme not found (#3989)

---
 modules/programs/kitty.nix | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/modules/programs/kitty.nix b/modules/programs/kitty.nix
index d9a3081d..698e8034 100644
--- a/modules/programs/kitty.nix
+++ b/modules/programs/kitty.nix
@@ -186,9 +186,13 @@ in {
 
         (optionalString (cfg.theme != null) ''
           include ${pkgs.kitty-themes}/share/kitty-themes/${
-            (head (filter (x: x.name == cfg.theme) (builtins.fromJSON
-              (builtins.readFile
-                "${pkgs.kitty-themes}/share/kitty-themes/themes.json")))).file
+            let
+              matching = filter (x: x.name == cfg.theme) (builtins.fromJSON
+                (builtins.readFile
+                  "${pkgs.kitty-themes}/share/kitty-themes/themes.json"));
+            in throwIf (length matching == 0)
+            "kitty-themes does not contain a theme named ${cfg.theme}"
+            (head matching).file
           }
         '')
         ''