in npm/cli/index.js [172:178]
function compileRelease() {
//Compile project in release mode
var command = 'mxmlc ' + path.join(process.cwd(), SOURCE_DIR_NAME , APP_START_FILE_NAME) + ' -debug=false';
console.log('Compiling release build...');
execSync(command);
console.log('Finished compiling');
}