Accessing gitub can be difficult at work; ssh tunneling is often blocked by firewalls and proxies make it difficult to use http.
The solution is to set the http_proxy environment variable;
You can now clone a public git repository over http.
However, this is only half the solution as private repositories use https so this setting doesn't work.
The solution is the similar https_proxy environment variable. Set this with the below command;
You can now clone public and private repositories with http and https through your companies proxy.