From 9ded51c865c06a59df725f367ecd9961ac51fd9c Mon Sep 17 00:00:00 2001
From: ahmza <hamza@ahmza.com>
Date: Wed, 5 Aug 2026 21:27:51 +0100
Subject: [PATCH] changes to move opencode to nixpkgs unstable - more up to
 date and fixes breaking bugs

---
 flake.lock                            | 19 ++++++++++++-
 flake.nix                             |  1 +
 modules/attrs/development/default.nix |  4 ++-
 modules/dendritic.nix                 |  3 ++
 modules/system/core/default.nix       |  1 +
 modules/system/core/overlays.nix      | 40 +++++++++++++++++++++++++++
 6 files changed, 66 insertions(+), 2 deletions(-)
 create mode 100644 modules/system/core/overlays.nix

diff --git a/flake.lock b/flake.lock
index 10bde67..a574b19 100644
--- a/flake.lock
+++ b/flake.lock
@@ -66,12 +66,29 @@
         "type": "github"
       }
     },
+    "nixpkgs-unstable": {
+      "locked": {
+        "lastModified": 1785828668,
+        "narHash": "sha256-8fsyqeO+mJqvIzeO4xIpgJe/f7MTbbVTEC6RT6WSXNs=",
+        "owner": "nixos",
+        "repo": "nixpkgs",
+        "rev": "e72e4f299401a3689d4b3d5fc6496b11db7064eb",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nixos",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
     "root": {
       "inputs": {
         "flake-file": "flake-file",
         "flake-parts": "flake-parts",
         "import-tree": "import-tree",
-        "nixpkgs": "nixpkgs"
+        "nixpkgs": "nixpkgs",
+        "nixpkgs-unstable": "nixpkgs-unstable"
       }
     }
   },
diff --git a/flake.nix b/flake.nix
index 356d3d5..d4bbf14 100644
--- a/flake.nix
+++ b/flake.nix
@@ -11,5 +11,6 @@
     };
     import-tree.url = "github:vic/import-tree";
     nixpkgs.url = "github:nixos/nixpkgs/nixos-26.05";
+    nixpkgs-unstable.url = "github:nixos/nixpkgs/nixos-unstable";
   };
 }
diff --git a/modules/attrs/development/default.nix b/modules/attrs/development/default.nix
index e92c771..9fa053a 100644
--- a/modules/attrs/development/default.nix
+++ b/modules/attrs/development/default.nix
@@ -14,7 +14,9 @@
   in {
     imports = modules;
     environment.systemPackages = with pkgs; [
-      opencode
+      # nixos-26.05 ships 1.15.10 and opencode releases several times a week,
+      # so it is pinned to unstable. See modules/system/core/overlays.nix.
+      unstable.opencode
       devenv
       jellyfin-tui
     ];
diff --git a/modules/dendritic.nix b/modules/dendritic.nix
index 68befe8..4f5a128 100644
--- a/modules/dendritic.nix
+++ b/modules/dendritic.nix
@@ -12,5 +12,8 @@
     };
     import-tree.url = "github:vic/import-tree";
     nixpkgs.url = "github:nixos/nixpkgs/nixos-26.05";
+    # Escape hatch for packages that move faster than the stable channel.
+    # Consumed only through the `unstable` overlay, see modules/system/core/overlays.nix.
+    nixpkgs-unstable.url = "github:nixos/nixpkgs/nixos-unstable";
   };
 }
diff --git a/modules/system/core/default.nix b/modules/system/core/default.nix
index 1da10d0..e0475f6 100644
--- a/modules/system/core/default.nix
+++ b/modules/system/core/default.nix
@@ -12,6 +12,7 @@
       user
       bootloader
       nix
+      overlays
       hardware
       locale
       nix-ld
diff --git a/modules/system/core/overlays.nix b/modules/system/core/overlays.nix
new file mode 100644
index 0000000..5b409f0
--- /dev/null
+++ b/modules/system/core/overlays.nix
@@ -0,0 +1,40 @@
+{
+  self,
+  inputs,
+  ...
+}: {
+  # Escape hatch for packages that move faster than the stable channel.
+  #
+  # `pkgs.unstable.<name>` resolves against nixos-unstable while the rest of the
+  # system stays on nixos-26.05. Keep the number of consumers small and prefer
+  # stable unless there is a concrete reason; every unstable package drags a bit
+  # of the unstable closure (glibc, stdenv) in alongside the stable one.
+  #
+  # Bump with `nix flake update nixpkgs-unstable`.
+  flake.overlays.unstable = _final: prev: {
+    unstable = import inputs.nixpkgs-unstable {
+      inherit (prev.stdenv.hostPlatform) system;
+      # Carries allowUnfree (set in nix-settings.nix) into the unstable set.
+      inherit (prev) config;
+    };
+  };
+
+  # This flake has two independent `pkgs` instances, and the overlay has to be
+  # registered on both or `pkgs.unstable` would exist in some modules only:
+  #
+  #   1. the NixOS module system's `pkgs` - plain modules such as
+  #      modules/features/bun, modules/system/core
+  #   2. flake-parts' perSystem `pkgs` - modules built with `moduleWithSystem`,
+  #      such as modules/attrs/development, which ignore `nixpkgs.overlays`
+  flake.nixosModules.overlays = {...}: {
+    nixpkgs.overlays = [self.overlays.unstable];
+  };
+
+  perSystem = {system, ...}: {
+    _module.args.pkgs = import inputs.nixpkgs {
+      inherit system;
+      overlays = [self.overlays.unstable];
+      config.allowUnfree = true;
+    };
+  };
+}