rosversion roslaunch can't locate [roslaunch]
RLException: Invalid tag: Cannot load command parameter [rosversion]
You can't start a roscore anymore, because rosversion can't find roslaunch?
- Try
roscd <some_package>with a package you know you have installed. - If that doesn't work and if your
ROS_env variables are all set correctly, checkrospack profile. - If that doesn't yield a list of directories like below, check if your
ROS_PACKAGE_PATHcontains a lonepackage.xmlamidst the packages. For some reason, such a lone package.xml will prevent rospack from looking into the other folders, and thus it won't discover your installed modules.
$ # should look like his
$ rospack profile
Full tree crawl took 0.217425 seconds.
Directories marked with (*) contain no manifest. You may
want to delete these directories.
To get just of list of directories without manifests,
re-run the profile with --zombie-only
-------------------------------------------------------------
0.206863 /opt/ros/noetic/share
0.000770 * /opt/ros/noetic/share/...
...
$ # this is where error comes from
$ ll /opt/ros/noetic/share/
total 1060
drwxr-xr-x 262 root root 12288 Jun 28 16:35 ./
drwxr-xr-x 7 root root 4096 Mai 7 14:34 ../
drwxr-xr-x 5 root root 4096 Mai 7 14:34 actionlib/
drwxr-xr-x 4 root root 4096 Mai 7 14:34 actionlib_msgs/
drwxr-xr-x 5 root root 4096 Mai 7 14:34 actionlib_tutorials/
...
drwxr-xr-x 5 root root 4096 Mai 7 14:34 octomap_msgs/
drwxr-xr-x 3 root root 4096 Jun 7 08:30 octomap_ros/
-rw-r--r-- 1 root root 820 Jun 15 16:52 package.xml <--- culprit
drwxr-xr-x 3 root root 4096 Mai 7 14:34 pcl_conversions/
drwxr-xr-x 5 root root 4096 Mai 7 14:34 pcl_msgs/
...