curl -O https://media.readthedocs.org/dash/casperjs/latest/CasperJS.tgz
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 177 100 177 0 0 124 0 0:00:01 0:00:01 --:--:-- 124
tar xfz CasperJS.tgz
tar: Unrecognized archive format
tar: Error exit delayed from previous errors.
rake aborted!
Command failed with status (1): [tar xfz CasperJS.tgz...]
/Users/sindhus/dash-casperjs/Rakefile:7:in`block (2 levels) in <top (required)>'
/Users/sindhus/.rvm/gems/ruby-2.2.1/bin/ruby_executable_hooks:15:in `eval'
/Users/sindhus/.rvm/gems/ruby-2.2.1/bin/ruby_executable_hooks:15:in`<main>'
Tasks: TOP => default => docs:generate => docs:download
(See full trace by running task with --trace)
what am I missing?