When you run a program using
sudo what tends to happen is the sudo/root account fails to do anything useful on the internet. It times out trying to connect to systems to download updates that are required by elevated permissions.
We discovered using
sudo composer self-update failed to update the core instance of composer, not because of permissions, but because it could not get to the internet to download it.
Set the environment variables that get persisted within your
/etc/sudoers file by running:
$ sudo visudo
Seach for the line
and change it to
Defaults env_keep += "ftp_proxy http_proxy https_proxy no_proxy"
Now your proxy will be set within your sudo environment too.