From 40c21b15cdee8302afb5d89a140daf0114fdf147 Mon Sep 17 00:00:00 2001
From: Gaute Ravndal <gaute.ravndal@gmail.com>
Date: Sat, 10 Jan 2026 09:12:57 +0100
Subject: [PATCH] nixos/programs/fish: set absolute path in babelfishTranslate

Babelfish translates `source script.sh` to `argv0 < script.sh | source`,
which is impure, and breaks when babelfish isn't in `systemPackages`.

To fix this, exec babelfish with argv0 set to babelfish from the final
system.
---
 nixos/modules/programs/fish.nix | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/nixos/modules/programs/fish.nix b/nixos/modules/programs/fish.nix
index 98915f530e82..4c622bd7dcfc 100644
--- a/nixos/modules/programs/fish.nix
+++ b/nixos/modules/programs/fish.nix
@@ -48,7 +48,7 @@ let
     path: name:
     pkgs.runCommandLocal "${name}.fish" {
       nativeBuildInputs = [ pkgs.babelfish ];
-    } "babelfish < ${path} > $out;";
+    } "exec -a ${lib.getExe pkgs.babelfish} babelfish < ${path} > $out;";
 in
 {
   options = {