昨天就找不到这个包，今天再试了一下，还是没有

bash-3.2$ gem sources *** CURRENT SOURCES ***

http://ruby.taobao.org/ http://ruby.taobao.org/ http://ruby.taobao.org/ http://ruby.taobao.org/ http://ruby.taobao.org/ bash-3.2$ gem install execjs -v '1.4.0' ERROR: Could not find a valid gem 'execjs' (= 1.4.0) in any repository ERROR: Possible alternatives: execjs