Exceção de tubo quebrado no aplicativo Grails

dependencies {
        // specify dependencies here under either 'build', 'compile'

        compile 'c3p0:c3p0:0.9.1.2'
    }

beans {
    dataSource(BasicDataSource) {
        **url = "jdbc:mysql://127.0.0.1/db_name"**
        driverClassName = "com.mysql.jdbc.Driver"
        username = "root"
        password = "root"
        pooled = true
   }
}