I recently upgraded an app to rails 2.3 and on many pages on my local machine the top of the HTML body included something like this:

Set-Cookie: _myapp_session_id=BAh7B...; path=/; HttpOnly

I couldn’t figure out what was happening until I found this forum post which explained that the problem was related to passenger 2.0.6. To fix the problem I just needed to update the version of passenger I was running.

To update passenger (on a mac) was pretty simple. Just run the following 2 commands:

sudo gem install passenger
sudo passenger-install-apache2-module

Depending on how you set up your local apache instance, you may also need to update the config. I needed to update /etc/apache2/httpd.conf to

LoadModule passenger_module /Library/Ruby/Gems/1.8/gems/passenger-2.1.2/ext/apache2/mod_passenger.so
PassengerRoot /Library/Ruby/Gems/1.8/gems/passenger-2.1.2