`raise_if_conflicts': Unable to activate cramp-0.15.1, because rack-1.5.2 conflicts with rack (~> 1.3.2) (Gem::LoadError) 这个怎么解决?
rackup -v
Rack 1.2 (Release: 1.5)
那就把 cramp 删掉...
给项目加上 bundler 支持,让他找合适版本的 gem