helix: rework

packages/helix/languages.nix

@@ -1,22 +1,25 @@
 {
+  fetchFromGitHub,
+  rustPlatform,
   alejandra,
   basedpyright,
   bash-language-server,
   clang-tools,
   cmake-format,
   cmake-language-server,
+  deadnix,
   deno,
   dprint,
   formats,
   gdb,
+  kdePackages,
   lib,
   nil,
   ruff,
   shfmt,
-  kdePackages,
+  simple-completion-language-server,
   typescript-language-server,
   vscode-langservers-extracted,
-  simple-completion-language-server,
   zls,
   ...
 }: let
@@ -24,6 +27,22 @@
 
   toml = formats.toml {};
 
+  # a newer nil version, for pipes support.
+  newer-nil = nil.overrideAttrs (_: {
+    version = "unstable-02-06-2025";
+
+    src = fetchFromGitHub {
+      owner = "oxalica";
+      repo = "nil";
+      rev = "577d160da311cc7f5042038456a0713e9863d09e";
+      hash = "sha256-ggXU3RHv6NgWw+vc+HO4/9n0GPufhTIUjVuLci8Za8c=";
+    };
+    cargoDeps = rustPlatform.fetchCargoVendor {
+      inherit (newer-nil) src;
+      hash = "sha256-uZsLlFU9GKLvFllF7Kf5Q7HfN26KQojf4rvOb9p7Rjs=";
+    };
+  });
+
   helix-languages = {
     language = let
       mark = lang: {
@@ -186,10 +205,13 @@
       };
 
       nil = {
-        command = getExe nil;
+        command = getExe newer-nil;
         # alejandro
         config.nil.formatting.command = ["${getExe alejandra}" "-q"];
       };
+      deadnix = {
+        command = getExe deadnix;
+      };
 
       scls = {
         command = getExe simple-completion-language-server;