From: Tim Uckun Date: 2011-09-11T10:51:34+09:00 Subject: Problems with rubygems I am having some serious problems with rubygems and I can't figure out if the problem is with my machine or rubygems itself. Using ubuntu and rvm... gem install bundler ERROR: While executing gem ... (NoMethodError) undefined method `spec' for nil:NilClass $gem install rspec ERROR: While executing gem ... (Zlib::DataError) incorrect header check I have all the libraries installed (zlib-dev etc) so I am utterly baffled as to what is going on.