Update to nixpkgs-25.05 and use that in tests consistently (#4)

Author: soenkehahn

flake.lock

@@ -1,5 +1,5 @@
 {
-  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixos-25.05-small";
+  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixos-25.05";
   inputs.flake-utils.url = "github:numtide/flake-utils";
   inputs.cradle = {
     url = "github:garnix-io/cradle";

flake.nix

@@ -34,14 +34,14 @@ spec = around_ inTempDirectory $ do
         (workingDir ctx </> "flake.nix")
         [i|
           {
-            inputs.nixpkgs.url = "github:nixos/nixpkgs/2f913f37ac91d3dda25c9259f17dbedcf908a157";
+            inputs.nixpkgs.url = "github:nixos/nixpkgs/#{nixpkgs2505Commit}";
             outputs = { nixpkgs, ... }: {
               nixosConfigurations.a = (nixpkgs.lib.nixosSystem {
                 modules = [
                   {
                     networking.hostName = "a";
                     nixpkgs.hostPlatform = "x86_64-linux";
-                    system.stateVersion = "24.11";
+                    system.stateVersion = "25.05";
                   }
                 ];
               });
@@ -50,7 +50,7 @@ spec = around_ inTempDirectory $ do
                   {
                     networking.hostName = "b";
                     nixpkgs.hostPlatform = "x86_64-linux";
-                    system.stateVersion = "24.11";
+                    system.stateVersion = "25.05";
                   }
                 ];
               });
@@ -59,7 +59,7 @@ spec = around_ inTempDirectory $ do
                   {
                     networking.hostName = "c";
                     nixpkgs.hostPlatform = "x86_64-linux";
-                    system.stateVersion = "24.11";
+                    system.stateVersion = "25.05";
                   }
                 ];
               });
@@ -117,22 +117,22 @@ spec = around_ inTempDirectory $ do
       _ <- assertSuccess $ test ctx ["start", "server"]
       B.hPutStr ctx.stdin "echo foo\nexit\n"
       hSeek ctx.stdin AbsoluteSeek 0
-      (stdout <$> assertSuccess (test ctx ["ssh", "server"])) `shouldReturn` "foo\n"
+      (stdout <$> assertSuccess (test ctx ["ssh", "server"])) `shouldReturn` "foo\n\ESC]0;\a"
 
   it "can start multiple vms" $ do
     withContext $ \ctx -> do
       writeFile
         (workingDir ctx </> "flake.nix")
         [i|
           {
-            inputs.nixpkgs.url = "github:nixos/nixpkgs/2f913f37ac91d3dda25c9259f17dbedcf908a157";
+            inputs.nixpkgs.url = "github:nixos/nixpkgs/#{nixpkgs2505Commit}";
             outputs = { nixpkgs, ... }: {
               nixosConfigurations.a = (nixpkgs.lib.nixosSystem {
                 modules = [
                   {
                     networking.hostName = "a";
                     nixpkgs.hostPlatform = "x86_64-linux";
-                    system.stateVersion = "24.11";
+                    system.stateVersion = "25.05";
                   }
                 ];
               });
@@ -141,7 +141,7 @@ spec = around_ inTempDirectory $ do
                   {
                     networking.hostName = "b";
                     nixpkgs.hostPlatform = "x86_64-linux";
-                    system.stateVersion = "24.11";
+                    system.stateVersion = "25.05";
                   }
                 ];
               });
@@ -192,14 +192,14 @@ writeStandardFlake ctx addedModule = do
         cs
           [i|
             {
-              inputs.nixpkgs.url = "github:nixos/nixpkgs/2f913f37ac91d3dda25c9259f17dbedcf908a157";
+              inputs.nixpkgs.url = "github:nixos/nixpkgs/#{nixpkgs2505Commit}";
               outputs = { nixpkgs, ... }: {
                 nixosConfigurations.server = (nixpkgs.lib.nixosSystem {
                   modules = [
                     {
                       networking.hostName = "server";
                       nixpkgs.hostPlatform = "x86_64-linux";
-                      system.stateVersion = "24.11";
+                      system.stateVersion = "25.05";
                     }
                     (#{fromMaybe emptyModule addedModule})
                   ];
@@ -208,3 +208,6 @@ writeStandardFlake ctx addedModule = do
             }
           |]
   T.writeFile (ctx.workingDir </> "flake.nix") flake
+
+nixpkgs2505Commit :: Text
+nixpkgs2505Commit = "3ff0e34b1383648053bba8ed03f201d3466f90c9"