backup perform --trigger my_backup

这样是好的

sudo backup perform --trigger my_backup

这样就报错如下

/usr/local/lib/ruby/1.9.1/rubygems/dependency.rb:247:in `to_specs': Could not find backup (>= 0) amongst [] (Gem::LoadError)
    from /usr/local/lib/ruby/1.9.1/rubygems/dependency.rb:256:in `to_spec'
    from /usr/local/lib/ruby/1.9.1/rubygems.rb:1231:in `gem'
    from /usr/local/bin/backup:22:in `<main>'

我知道 gem 不支持 ruby-1.9.1 我把 1.9.1 都删掉了，可是还是会这样用 rvm remove 删掉的。。为什么会这样？？求解？