repo init - fatal: unable to connect to github.com

[johnea]

repo init -u git://github.com/minimal-manifest-twrp/platform_manifest_twrp_omni.git -b twrp-10.0

manifests:
fatal: unable to connect to github.com:
github.com[0: 192.30.255.112]: errno=Connection timed out

[twrp]$ ping -c1 192.30.255.112
PING 192.30.255.112 (192.30.255.112) 56(84) bytes of data.
64 bytes from 192.30.255.112: icmp_seq=1 ttl=44 time=36.2 ms

--- 192.30.255.112 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 36.195/36.195/36.195/0.000 ms