[ruby] Can't install gems on OS X "El Capitan"

That is because of the new security function of OS X "El Capitan". Try adding --user-install instead of using sudo:

$ gem install *** --user-install

For example, if you want to install fake3 just use:

$ gem install fake3 --user-install

Examples related to ruby

Uninitialized Constant MessagesController Embed ruby within URL : Middleman Blog Titlecase all entries into a form_for text field Ruby - ignore "exit" in code Empty brackets '[]' appearing when using .where find_spec_for_exe': can't find gem bundler (>= 0.a) (Gem::GemNotFoundException) How to update Ruby Version 2.0.0 to the latest version in Mac OSX Yosemite? How to fix "Your Ruby version is 2.3.0, but your Gemfile specified 2.2.5" while server starting Is the server running on host "localhost" (::1) and accepting TCP/IP connections on port 5432? How to update Ruby with Homebrew?

Examples related to macos

Problems with installation of Google App Engine SDK for php in OS X dyld: Library not loaded: /usr/local/opt/openssl/lib/libssl.1.0.0.dylib dyld: Library not loaded: /usr/local/opt/icu4c/lib/libicui18n.62.dylib error running php after installing node with brew on Mac Could not install packages due to an EnvironmentError: [Errno 13] How do I install Java on Mac OSX allowing version switching? Git is not working after macOS Update (xcrun: error: invalid active developer path (/Library/Developer/CommandLineTools) Can't compile C program on a Mac after upgrade to Mojave You don't have write permissions for the /Library/Ruby/Gems/2.3.0 directory. (mac user) How can I install a previous version of Python 3 in macOS using homebrew? Could not install packages due to a "Environment error :[error 13]: permission denied : 'usr/local/bin/f2py'"

Examples related to rubygems

You don't have write permissions for the /Library/Ruby/Gems/2.3.0 directory. (mac user) find_spec_for_exe': can't find gem bundler (>= 0.a) (Gem::GemNotFoundException) How to fix "Your Ruby version is 2.3.0, but your Gemfile specified 2.2.5" while server starting You don't have write permissions for the /var/lib/gems/2.3.0 directory Can't install gems on OS X "El Capitan" How to avoid "cannot load such file -- utils/popen" from homebrew on OSX How can I set a proxy server for gem? How to install CocoaPods? Error while installing json gem 'mkmf.rb can't find header files for ruby' How to downgrade or install an older version of Cocoapods