Whenever I run a Rails app, I had to access it via http://0.0.0:port_number. Devise Rails plugin sample app barks when redirecting with this error message:
ERROR URI::InvalidURIError: the scheme http does not accept registry part: 0.0.0:3000 (or bad hostname?)
1) To cleanup the mess, I edited the /etc/hosts file so it now looks like this:
# Host Database
# localhost is used to configure the loopback interface
# when the system is booting. Do not change this entry.
2) Then flush the cache to pickup the new changes by running :
sudo dscacheutil -flushcache
Now you can access your local Rails apps by : http://localhost:port_number and Devise is happy again.