OSX上的Ruby进程持续超过90％。这是怎么回事？

I have a handful of Ruby/Rails apps I'm building locally. I've noticed lately that no matter which app I'm working on, my Ruby process will build up to 90+%, the CPU fan will kick on, and there's no stopping it unless I kill the sucker. Doesn't seem to matter which app I'm working on. Any ideas? Any way to track what's wrong?I have a handful of Ruby/Rails apps I'm buildin