$ sudo apt-get install ros-melodic-navigation [sudo] password for user: Reading package lists... Done Building dependency tree Reading state information... Done ros-melodic-navigation is already the newest version (1.16.6-1bionic.20200530.114248). The following packages were automatically installed and are no longer required: linux-headers-5.3.0-51 linux-headers-5.3.0-51-generic linux-image-5.3.0-51-generic linux-modules-5.3.0-51-generic linux-modules-extra-5.3.0-51-generic Use 'sudo apt autoremove' to remove them. 0 upgraded, 0 newly installed, 0 to remove and 300 not upgraded.
I can find the navigation package with:
$ apt list | grep navigation ... ros-melodic-navigation/bionic,now 1.16.6-1bionic.20200530.114248 amd64 [installed] ...
But when I try it with
rospack, I get an error
rospack find navigation [rospack] Error: package 'navigation' not found
What is the issue here?