Implement distributed builder

nix/configuration.nix

@@ -18,6 +18,24 @@ in rec {
     users.julian = import ./home.nix;
   };
 
+ nix.buildMachines = [ {
+	 hostName = "192.168.3.118";
+	 system = "x86_64-linux";
+	 protocol = "ssh";
+        # if the builder supports building for multiple architectures, 
+        # replace the previous line by, e.g.
+        # systems = ["x86_64-linux" "aarch64-linux"];
+	 maxJobs = 4;
+	 speedFactor = 3;
+	 supportedFeatures = [ "nixos-test" "benchmark" "big-parallel" "kvm" ];
+	 mandatoryFeatures = [ ];
+}] ;
+	nix.distributedBuilds = true;
+       # optional, useful when the builder has a faster internet connection than yours
+	nix.extraOptions = ''
+	  builders-use-substitutes = true
+	'';
+
   # Bootloader
   # Use this for simple nix boot menu, if no dual boot required
   boot.loader.systemd-boot.enable = true;
@@ -62,6 +80,17 @@ in rec {
   nix.settings.auto-optimise-store = true;
   nix.settings.experimental-features = [ "nix-command" "flakes" ];
 
+  # Setup binary caches
+  nix.settings = {
+  	substituters = [
+	"https://nix-community.cachix.org"
+	"https://cache.nixos.org/"
+	];
+	trusted-public-keys = [
+	"nix-community.cachix.org-1:mB9FSh9qf2dCimDSUo8Zy7bkq5CX+/rkCWyvRCYg3Fs="
+	];
+  };
+
   # Enable the X11 windowing system.
   services.xserver.enable = true;
   services.xserver.videoDrivers = [ "nvidia" ];
@@ -201,6 +230,9 @@ in rec {
 
   services.flatpak.enable = true;
 
+  # Smart card reader
+  services.pcscd.enable = true;
+
   xdg.portal.enable = true;
   xdg.portal.extraPortals = [ pkgs.xdg-desktop-portal-gtk ];
 
@@ -212,8 +244,20 @@ in rec {
   # $ nix search wget
 
   environment.systemPackages = with pkgs; [
+    # rfid reader tests
+    openct
+    opensc
+    pcsclite
+    pcsctools
+    ccid
+    libnfc
+
+    xournalpp
+    path-of-building
+
     xfce.thunar-archive-plugin
     zip
+    p7zip
     imagemagick
     (pkgs.python3.withPackages python-packages)
     firefox
@@ -317,10 +361,11 @@ in rec {
     xclip
     okular # Pdf reader with many features, good for commenting documents
     evince # Simple pdf reader, good for focusing on document content
+    pdfsam-basic # Split, merge, etc for pdfs
 
     poppler_utils # Pdf utils including pdfimages
     matlab # Using nix-matlab overlay defined in flake
-    sage
+    # sage
 
     gimp
 
@@ -340,6 +385,10 @@ in rec {
     calibre
 
     audible-cli
+
+    cudaPackages.cudatoolkit 
+    openmvg
+    colmapWithCuda
   ];
 
   nixpkgs.overlays = [