```ruby
describe 'xserver installation' do
  describe command('Xorg -version') do
    its(:exit_status) { should eq 0 }
  end

  describe command('DISPLAY=:99.0 xset -q') do
    its(:stdout) { should match(/^Keyboard Control:/) }
    its(:exit_status) { should eq 0 }
  end

  describe command('DISPLAY=:99.0 xvfb-run xdpyinfo') do
    its(:stdout) { should match(/^\s+GLX$/) }
    its(:exit_status) { should eq 0 }
  end
end
```

Tag xdpyinfo spec `dev:true` (for now)
user
```ruby
describe 'xserver installation' do
  describe command('Xorg -version') do
    its(:exit_status) { should eq 0 }
  end

  describe command('DISPLAY=:99.0 xset -q') do
    its(:stdout) { should match(/^Keyboard Control:/) }
    its(:exit_status) { should eq 0 }
  end

  describe command('DISPLAY=:99.0 xvfb-run xdpyinfo'), dev: true do
    its(:stdout) { should match(/^\s+GLX$/) }
    its(:exit_status) { should eq 0 }
  end
end
```
assistant