From 41ab7354c1f06313bed3c2e92762cb660dd82f61 Mon Sep 17 00:00:00 2001
From: Manuel Thalmann <m@nuth.ch>
Date: Mon, 25 Nov 2024 15:19:13 +0100
Subject: [PATCH] Ensure nix channels are functioning

---
 scripts/lib/nix.fish | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/scripts/lib/nix.fish b/scripts/lib/nix.fish
index f61cb698..7f44084d 100644
--- a/scripts/lib/nix.fish
+++ b/scripts/lib/nix.fish
@@ -3,10 +3,14 @@ begin
     set -l config "$dir/config.fish"
     set nixPkgsDir "/nix/var/nix/profiles/per-user/root/channels/nixpkgs"
 
+    function __isNixModule -a path
+        nix-instantiate --eval --expr "{ path }: import path" --argstr path "$path" &>/dev/null
+    end
+
     function downloadNixPkgs -V config
         source "$config"
 
-        if [ ! -d "$nixPkgsCache" ]
+        if ! __isNixModule "$nixPkgsCache"
             mkdir -p "$nixPkgsCache"
             and git clone https://github.com/NixOS/nixpkgs.git --depth=1 -b "$nixPkgsVersion" "$nixPkgsCache"
             and rm -rf "$nixPkgsCache/.git"
@@ -16,8 +20,8 @@ begin
     function installNixPkgs -V config -V nixPkgsDir
         source "$config"
 
-        if [ ! -d "$nixPkgsDir" ]
-            if [ ! -d "$nixPkgsCache" ]
+        if ! __isNixModule "$nixPkgsDir"
+            if ! __isNixModule "$nixPkgsCache"
                 downloadNixPkgs
             end