How to use PEAR behind proxy?
Instead of using the system's http_proxy, set the proxy directly in pear's config;
pear config-set http_proxy http://username:password@yourproxy:80
You also may have an issue with your sudo user having different configuration from your user for pear.
If you make this :
pear config-set http_proxy http://username:password@yourproxy:80
Then
sudo pear channel-discover pear.symfony-project.com
You have change user and the proxy is still not set.
So use the appropriate command:
sudo pear config-set http_proxy http://username:password@yourproxy:80
(Issue spotted on Ubuntu 11.04 fresh install)