#rosdep init# fails

error:

~$ sudo rosdep init
[sudo] password for yyd: 
ERROR: cannot download default sources list from:
https://raw.githubusercontent.com/ros/rosdistro/master/rosdep/sources.list.d/20-default.list
Website may be down.

solution:

#There's something odd about how the certificates on the TX1 image were installed. 

sudo c_rehash /etc/ssl/certs

result:

~$ sudo c_rehash /etc/ssl/certs
Doing /etc/ssl/certs
WARNING: Skipping duplicate certificate ca-certificates.crt
WARNING: Skipping duplicate certificate ca-certificates.crt
~$ sudo rosdep init
Wrote /etc/ros/rosdep/sources.list.d/20-default.list
Recommended: please run

	rosdep update