From d2d707ecc32ebeed7754b3368616b1c1e13b8fdc Mon Sep 17 00:00:00 2001
From: Harald Hoyer <harald@subzero.xyz>
Date: Thu, 13 Nov 2025 13:20:06 +0100
Subject: [PATCH] chore(nixbuild): add supportedFeatures to builder configs

- Introduced `supportedFeatures` to each builder for better control over build capabilities (`nixos-test`, `benchmark`, `big-parallel`, and `kvm` for SGX).
- Enabled `builders-use-substitutes` setting to optimize build efficiency.
---
 systems/nixbuild.nix | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/systems/nixbuild.nix b/systems/nixbuild.nix
index fd92e53..0b898af 100644
--- a/systems/nixbuild.nix
+++ b/systems/nixbuild.nix
@@ -10,6 +10,11 @@
       speedFactor = 3;
       sshUser = "harald";
       sshKey = "/etc/ssh/nix-builder-key";
+      supportedFeatures = [
+        "nixos-test"
+        "benchmark"
+        "big-parallel"
+      ];
     }
     {
       hostName = "rialo";
@@ -18,6 +23,11 @@
       speedFactor = 3;
       sshUser = "harald";
       sshKey = "/etc/ssh/nix-builder-key";
+      supportedFeatures = [
+        "nixos-test"
+        "benchmark"
+        "big-parallel"
+      ];
     }
     {
       hostName = "sgx";
@@ -26,9 +36,17 @@
       speedFactor = 1;
       sshUser = "harald";
       sshKey = "/etc/ssh/nix-builder-key";
+      supportedFeatures = [
+        "nixos-test"
+        "benchmark"
+        "big-parallel"
+        "kvm"
+      ];
     }
   ];
 
+  nix.settings.builders-use-substitutes = true;
+
   # Ensure Nix is in PATH for SSH sessions
   programs.fish.shellInit = ''
     set -gx PATH /nix/var/nix/profiles/default/bin $PATH