每当gem错误没有此类文件或目录时-crontab

我不知道这是什么问题。这是我的问题

这是控制台输出。

$ whenever --update-crontab
Системе не удается найти указанный путь.
C:/RailsInstaller/Ruby2.3.3/lib/ruby/gems/2.3.0/gems/whenever-0.10.0/lib/whenever/command_line.rb:77:in `popen': No such file or directory - crontab - (Errno::ENOENT)
        from C:/RailsInstaller/Ruby2.3.3/lib/ruby/gems/2.3.0/gems/whenever-0.10.0/lib/whenever/command_line.rb:77:in `write_crontab'
        from C:/RailsInstaller/Ruby2.3.3/lib/ruby/gems/2.3.0/gems/whenever-0.10.0/lib/whenever/command_line.rb:38:in `run'
        from C:/RailsInstaller/Ruby2.3.3/lib/ruby/gems/2.3.0/gems/whenever-0.10.0/lib/whenever/command_line.rb:6:in `execute'
        from C:/RailsInstaller/Ruby2.3.3/lib/ruby/gems/2.3.0/gems/whenever-0.10.0/bin/whenever:44:in `<top (required)>'
        from C:/RailsInstaller/Ruby2.3.3/bin/whenever:22:in `load'
        from C:/RailsInstaller/Ruby2.3.3/bin/whenever:22:in `<main>'