fix: more nix issues

Package.swift

@@ -1,4 +1,4 @@
-// swift-tools-version:5.3
+// swift-tools-version:5.9
 // The swift-tools-version declares the minimum version of Swift required to build this package.
 
 import PackageDescription

Sources/WireGuardKitC/WireGuardKitC.h

@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: MIT
 // Copyright © 2018-2023 WireGuard LLC. All Rights Reserved.
 
+#include <sys/types.h>
 #include "key.h"
 #include "x25519.h"
 

Sources/WireGuardKitGo/Makefile

@@ -20,16 +20,18 @@ GOARCH_arm64 := arm64
 GOARCH_x86_64 := amd64
 GOOS_macosx := darwin
 GOOS_iphoneos := ios
+GOOS_iphonesimulator := ios
 
 build: $(DESTDIR)/libwg-go.a
 version-header: $(DESTDIR)/wireguard-go-version.h
 
-REAL_GOROOT := $(shell go env GOROOT 2>/dev/null)
+REAL_GOROOT := $(shell export PATH="$(PATH):/usr/local/bin:/opt/homebrew/bin"; go env GOROOT 2>/dev/null)
 export GOROOT := $(BUILDDIR)/goroot
 $(GOROOT)/.prepared:
 	[ -n "$(REAL_GOROOT)" ]
 	mkdir -p "$(GOROOT)"
 	rsync -a --delete --exclude=pkg/obj/go-build "$(REAL_GOROOT)/" "$(GOROOT)/"
+	chmod -R u+w "$(GOROOT)"
 	cat goruntime-*.diff | patch -p1 -f -N -r- -d "$(GOROOT)"
 	touch "$@"