Update nix stuff

flake.lock

@@ -40,11 +40,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1755268003,
-        "narHash": "sha256-nNaeJjo861wFR0tjHDyCnHs1rbRtrMgxAKMoig9Sj/w=",
+        "lastModified": 1758916627,
+        "narHash": "sha256-fB2ISCc+xn+9hZ6gOsABxSBcsCgLCjbJ5bC6U9bPzQ4=",
         "owner": "nixos",
         "repo": "nixpkgs",
-        "rev": "32f313e49e42f715491e1ea7b306a87c16fe0388",
+        "rev": "53614373268559d054c080d070cfc732dbe68ac4",
         "type": "github"
       },
       "original": {

flake.nix

@@ -22,9 +22,29 @@ rec {
       "x86_64-linux"
     ]
     (system: let
+      # Overlay: bump go_1_25 to 1.25.1 while nixpkgs-unstable lags behind
+      # https://nixpk.gs/pr-tracker.html?pr=441125 / https://github.com/NixOS/nixpkgs/pull/441125
+      # https://github.com/NixOS/nixpkgs/issues/440982
+      go1251Overlay = (final: prev:
+        let
+          newVersion = "1.25.1";
+        in {
+          go_1_25 = prev.go_1_25.overrideAttrs (old: {
+            version = newVersion;
+            src = prev.fetchurl {
+              url = "https://go.dev/dl/go${newVersion}.src.tar.gz";
+              hash = "sha256-0BDBCc7pTYDv5oHqtGvepJGskGv0ZYPDLp8NuwvRpZQ=";
+            };
+          });
+          # ensure pkgs.go resolves to the bumped compiler
+          go = final.go_1_25;
+        });
       pkgs = import nixpkgs {
         inherit system;
-        overlays = [devshell.overlays.default];
+        overlays = [
+          devshell.overlays.default
+          go1251Overlay
+        ];
       };
     in rec {
       formatter = pkgs.alejandra;
@@ -57,6 +77,8 @@ rec {
           pkgs.nodejs-slim_22
           pkgs.pnpm_10
           pkgs.typescript-language-server
+          pkgs.mise
+          pkgs.mkcert
         ];
         env = [];
       };