ERROR: Error installing capybara-webkit:

Question

If you are in Ubuntu do

sudo apt-get install qt4-dev-tools libqt4-dev libqt4-core libqt4-gui

If you are on Mac

brew install qt

and then

gem install capybara-webkit -v '0.11.0'

For Ubuntu 16.04

sudo apt-get install qt-sdk

Followed by

gem install capybara-webkit -v '1.11.0' or replace with whatever version you want to install.

You are probably missing the qt libraries. See the capybara-webkit wiki for instructions on installing them for your platform.

brew install qt will only install (as of August 4, 2015) 4.8.6, which gives you this message.

WARNING: The next major version of capybara-webkit will require at least version 5.0 of Qt. You're using version 4.8.6.

Instead, if you do

brew install qt5
brew link --force qt5

you won't get that error.

On El Capitan or Yosemite, you may need to do brew install qt55 according to the doc here.