add ccache

fake_flake.nix

@@ -59,6 +59,9 @@ in
     distro = "${distroName} ${version} (${codeName}) ${system}";
   };
 
+  nix.settings.extra-sandbox-paths = [ config.programs.ccache.cacheDir ];
+  programs.ccache.enable = true;
+
   environment.systemPackages =
     with pkgs;
     with lib;

overlays/ccache-wrapper.nix

@@ -0,0 +1,31 @@
+{
+  final,
+  prev,
+  config,
+  ...
+}:
+{
+  ccacheWrapper = prev.ccacheWrapper.override {
+    extraConfig = ''
+      export CCACHE_COMPRESS=1
+      export CCACHE_DIR="${config.programs.ccache.cacheDir}"
+      export CCACHE_UMASK=007
+      if [ ! -d "$CCACHE_DIR" ]; then
+        echo "====="
+        echo "Directory '$CCACHE_DIR' does not exist"
+        echo "Please create it with:"
+        echo "  sudo mkdir -m0770 '$CCACHE_DIR'"
+        echo "  sudo chown root:nixbld '$CCACHE_DIR'"
+        echo "====="
+        exit 1
+      fi
+      if [ ! -w "$CCACHE_DIR" ]; then
+        echo "====="
+        echo "Directory '$CCACHE_DIR' is not accessible for user $(whoami)"
+        echo "Please verify its access permissions"
+        echo "====="
+        exit 1
+      fi
+    '';
+  };
+}

overlays/default.nix

@@ -21,5 +21,6 @@
         ./deskwhich.nix
         ./mcontrolcenter.nix
         ./the-powder-toy.nix
+        ./ccache-wrapper.nix
       ];
 }

overlays/matrix-appservice-discord.nix

@@ -14,7 +14,7 @@
         in
         if oldPatches == null then [ ] else oldPatches
       )
-          ++ [ ./patches/bridge_perms.patch ];
+      ++ [ ../patches/bridge_perms.patch ];
     doCheck = false;
   });
 }

patches/lix-ccache.patch

@@ -0,0 +1,22 @@
+diff --git a/package.nix b/package.nix
+index 0186b7472..da783e152 100644
+--- a/package.nix
++++ b/package.nix
+@@ -1,7 +1,7 @@
+ {
+   pkgs,
+   lib,
+-  stdenv,
++  ccacheStdenv,
+   aws-sdk-cpp,
+   # If the patched version of Boehm isn't passed, then patch it based off of
+   # pkgs.boehmgc. This allows `callPackage`ing this file without needing to
+@@ -81,6 +81,8 @@ let
+   inherit (__forDefaults) canRunInstalled;
+   inherit (lib) fileset;
+ 
++  stdenv = ccacheStdenv;
++
+   version = lib.fileContents ./.version + versionSuffix;
+ 
+   aws-sdk-cpp-nix = aws-sdk-cpp.override {