?

flake.nix

@@ -24,8 +24,16 @@
       # the library actually gets installed to the nix store output
       installPhase = ''
         mkdir -p $out/lib $out/include
-        cp libPROCESSOR.dylib $out/lib/ 2>/dev/null || cp libPROCESSOR.a $out/lib/
+
-        cp *.h $out/include/
+        # Copy the library (looks like your build made a static lib 'libPROCESSOR.a')
+        cp libPROCESSOR.a $out/lib/
+
+        # Copy headers safely.
+        # If your headers are in a subfolder, change './*.h' to './src/*.h' etc.
+        # The '|| true' ensures the build doesn't crash if no headers are found.
+        cp *.h $out/include/ || cp src/*.h $out/include/ || true
+
+        echo "✅ Installed libPROCESSOR.a and headers to $out"
       '';
     };