WIP: Add ability to modify platform.txt via mkArduinoPackageOverlay

flake.nix

@@ -2,9 +2,10 @@
   description = "Wrapper for arduino-cli";
 
   outputs = { self }: {
-    mkArduinoPackageOverlay = packageIndexFile: (self: super: {
+    mkArduinoPackageOverlay = { packageIndexFile, buildProperties ? {} }: (self: super: {
       arduinoPackages = self.lib.recursiveUpdate (super.arduinoPackages or {}) (self.callPackage ./packages.nix {
         packageIndex = builtins.fromJSON (builtins.readFile packageIndexFile);
+        buildProperties = buildProperties;
       });
     });
 

packages.nix

@@ -1,4 +1,4 @@
-{ fetchzip, stdenv, lib, packageIndex, pkgsBuildHost, pkgs, arduinoPackages }:
+{ fetchzip, stdenv, lib, packageIndex, buildProperties, pkgsBuildHost, pkgs, arduinoPackages }:
 
 with builtins;
 let
@@ -57,6 +57,21 @@ let
 
           runHook postInstall
         '';
+        fixupPhase = ''
+          # Iterate over each key-value pair in buildProperties
+          # and append/update it accordingly in platform.txt
+          ${
+            pkgs.lib.concatStringsSep "\n" (pkgs.lib.mapAttrsToList (key: value: ''
+            if grep -q "^${key}=" "$out/$dirName/platform.txt"; then
+              # If the line exists, use sed to replace it
+              sed -i "s|^${key}=.*|& ${value}|" "$out/$dirName/platform.txt"
+            else
+              # If the line doesn't exist, add it at the end of the file
+              echo "${key}=${value}" >> "$out/$dirName/platform.txt"
+            fi
+            '') buildProperties)
+          }
+        '';
         nativeBuildInputs = [ pkgs.unzip ];
         src = fetchurl ({
           url = url;