TL;DR if you are using an EOL ROS distribution you will from now on need to pass the option
.yaml files which define the mapping of rosdep keys to system packages as well as enumerate all ROS packages for each ROS distribution.
Until recently when calling
rosdep update to fetch the latest information the tool was fetching a
.yaml file for every ROS distribution since
groovy. Since the number of ROS distributions is continuously increasing the time it takes to fetch these files was increasing to. With the roll out of REP 153 we finally have meta information about each ROS distribution and know which ones are end-of-life. With that knowledge newer versions of rosdep (as of 0.14.0) won’t by default fetch information for EOLed ROS distributions anymore.
I you happen to still use an EOL ROS distro and want to keep using
rosdep you can invoke it with the new option
--include-eol-distros to keep fetching information about all ROS distributions.