运行

dong@ubuntu:~/octopress$ gem install therubyracer  

报错

ERROR:  Error installing therubyracer:
    invalid gem: package is corrupt, exception while verifying: undefined method `size' for nil:NilClass (NoMethodError) in /home/dong/.rvm/gems/ruby-2.3.1/cache/libv8-3.16.14.15-x86_64-linux.gem

corrupt:broken
the package is broken
so remove /home/dong/.rvm/gems/ruby-2.3.1/cache/libv8-3.16.14.15-x86_64-linux.gem
then redownload and reinstall
successed.