Update, this error occurred when using the polymer version found on the GitHub. The issue was resolved when I downloaded v4.17beta2 from this website and operated out of the included polymer-v4.17beta2 folder

Hello, I am having trouble during the make step in v4.17beta2 when compiling with cython. The terminal output is as follows: RuntimeError: An attempt has been made to start a new process before the current process has finished its bootstrapping phase. This probably means that you are not using fork ...