How to setup JavaScriptCore on MacOS 13.4 1. Install and configure Xcode # install xcode command line tool $ xcode-select --install # Make sure xcode path is properly set $ xcode-select -p # output: /Applications/Xcode.app/Contents/Developer # check installed version $ xcodebuild -version 2. Install cmake brew install cmake 3. Clone Webkit repository on Github git clone git://git.webkit.org/WebKit.git WebKit.git && WebKit.git 4. Build Webkit ./Tools/Scripts/build-webkit --tsc-only --debug 5. Test JSCore with REPL Prompt ./WebKitBuild/Debug/bin/jsc