While following the tutorial, I get an error every time I run rospack depends or rospack depends1:

~> rospack depends1 rospy
ImportError: No module named rosdep2.rospack
ImportError: No module named rosdep2.rospack
[rospack] Error: could not find python module 'rosdep2.rospack'. is rosdep up-to-date (at least 0.10.4)?

The problem started after Ubuntu installed some updates, including updates for ros-melodic. I am pasting the log with the list of updates at the bottom of this post.

To try and fix it I have re-installed python-rosdep, run again sudo rosdep init and rosdep update, but no change.

Running Melodic under Ubuntu 18.04, on a x86 PC.

Here the rosdep I have installed

~> sudo apt list --installed | grep rosdep

WARNING: apt does not have a stable CLI interface. Use with caution in scripts.

python-rosdep/bionic,bionic,now 0.18.0-1 all [installed]
python-rosdep-modules/bionic,bionic,now 0.18.0-1 all [installed,automatic]

And the environment

~> env | grep ROS
ROS_ETC_DIR=/opt/ros/melodic/etc/ros
ROS_ROOT=/opt/ros/melodic/share/ros
ROS_MASTER_URI=http://localhost:11311
ROS_VERSION=1
ROS_PYTHON_VERSION=2
ROS_PACKAGE_PATH=/home/fanta/workspace/robotics_lab/src:/opt/ros/melodic/share
ROSLISP_PACKAGE_DIRECTORIES=/home/fanta/workspace/robotics_lab/devel/share/common-lisp
ROS_DISTRO=melodic

Here the list of updates applied before the problem started:

Start-Date: 2019-12-11 12:06:43 Commandline: aptdaemon role='role-commit-packages' sender=':1.133' Upgrade: ros-melodic-qt-gui-cpp:amd64 (0.3.15-1bionic.20191023.174305, 0.3.16-1bionic.20191205.001935), ros-melodic-rqt-runtime-monitor:amd64 (0.5.7-0bionic.20191023.174233, 0.5.7-0bionic.20191205.001357), ros-melodic-voxel-grid:amd64 (1.16.2-0bionic.20191008.165335, 1.16.3-1bionic.20191120.164956), ros-melodic-diff-drive-controller:amd64 (0.15.0-0bionic.20191008.202822, 0.15.0-0bionic.20191127.153015), ros-melodic-carrot-planner:amd64 (1.16.2-0bionic.20191008.212102, 1.16.3-1bionic.20191120.171202), ros-melodic-simulators:amd64 (1.4.1-0bionic.20191109.020208, 1.4.1-0bionic.20191205.003437), ros-melodic-control-toolbox:amd64 (1.17.0-0bionic.20191008.201417, 1.17.0-0bionic.20191127.153625), ros-melodic-gazebo-ros-control:amd64 (2.8.4-0bionic.20191008.205320, 2.8.4-0bionic.20191127.154941), ros-melodic-robot:amd64 (1.4.1-0bionic.20191109.020035, 1.4.1-0bionic.20191127.152703), ros-melodic-rviz:amd64 (1.13.5-1bionic.20191008.205203, 1.13.6-1bionic.20191125.133538), ros-melodic-librviz-tutorial:amd64 (0.10.3-0bionic.20191008.212608, 0.10.3-0bionic.20191125.142053), ros-melodic-rotate-recovery:amd64 (1.16.2-0bionic.20191008.212138, 1.16.3-1bionic.20191120.171208), libssh-4:amd64 (0.8.0~20170825.94fa1e38-1ubuntu0.2, 0.8.0~20170825.94fa1e38-1ubuntu0.5), ros-melodic-rqt-py-console:amd64 (0.4.8-0bionic.20191023.174341, 0.4.8-0bionic.20191205.001350), libwbclient0:amd64 (2:4.7.6+dfsg~ubuntu-0ubuntu2.13, 2:4.7.6+dfsg~ubuntu-0ubuntu2.14), git-man:amd64 (1:2.17.1-1ubuntu0.4, 1:2.17.1-1ubuntu0.5), ros-melodic-rqt-image-view:amd64 (0.4.13-0bionic.20191023.175528, 0.4.13-0bionic.20191205.002903), ros-melodic-desktop:amd64 (1.4.1-0bionic.20191109.020203, 1.4.1-0bionic.20191205.003520), ros-melodic-visualization-tutorials:amd64 (0.10.3-0bionic.20191008.213608, 0.10.3-0bionic.20191125.143834), ros-melodic-rqt-service-caller:amd64 (0.4.8-0bionic.20191023.174254, 0.4.8-0bionic.20191205.001639), ros-melodic-rqt-publisher:amd64 (0.4.8-0bionic.20191023.174258, 0.4.8-0bionic.20191205.001500), ros-melodic-rviz-python-tutorial:amd64 (0.10.3-0bionic.20191008.212642, 0.10.3-0bionic.20191125.142722), ros-melodic-rqt-topic:amd64 (0.4.10-0bionic.20191023.174344, 0.4.10-0bionic.20191205.001753), ros-melodic-rqt-gui-cpp:amd64 (0.5.0-0bionic.20191023.174822, 0.5.0-0bionic.20191205.002535), git:amd64 (1:2.17.1-1ubuntu0.4, 1:2.17.1-1ubuntu0.5), ros-melodic-rqt-bag:amd64 (0.4.12-0bionic.20191023.174603, 0.4.12-0bionic.20191205.001725), ros-melodic-rqt-robot-dashboard:amd64 (0.5.7-0bionic.20191023.175229, 0.5.7-0bionic.20191205.001926), ros-melodic-rqt-common-plugins:amd64 (0.4.8-0bionic.20191105.194801, 0.4.8-0bionic.20191205.003358), ros-melodic-rqt-launch:amd64 (0.4.8-0bionic.20191023.175117, 0.4.8-0bionic.20191205.001909), ros-melodic-rqt-plot:amd64 (0.4.9-0bionic.20191023.174649, 0.4.9-0bionic.20191205.001208), ros-melodic-rqt-robot-steering:amd64 (0.5.9-0bionic.20191023.174221, 0.5.10-1bionic.20191205.001735), ros-melodic-effort-controllers:amd64 (0.15.0-0bionic.20191008.202229, 0.15.0-0bionic.20191127.154002), ros-melodic-rqt-dep:amd64 (0.4.9-0bionic.20191023.174716, 0.4.9-0bionic.20191205.001629), ros-melodic-dwa-local-planner:amd64 (1.16.2-0bionic.20191008.212111, 1.16.3-1bionic.20191120.171207), ros-melodic-costmap-2d:amd64 (1.16.2-0bionic.20191008.205156, 1.16.3-1bionic.20191120.165427), ros-melodic-base-local-planner:amd64 (1.16.2-0bionic.20191008.211026, 1.16.3-1bionic.20191120.170539), ros-melodic-move-slow-and-clear:amd64 (1.16.2-0bionic.20191008.211050, 1.16.3-1bionic.20191120.170553), ros-melodic-rqt-gui:amd64 (0.5.0-0bionic.20191023.173644, 0.5.0-0bionic.20191205.000437), ros-melodic-control-msgs:amd64 (1.5.0-0bionic.20191008.171946, 1.5.1-1bionic.20191127.152354), ros-melodic-rqt-action:amd64 (0.4.9-0bionic.20191023.175138, 0.4.9-0bionic.20191205.002108), thunderbird-gnome-support:amd64 (1:68.2.1+build1-0ubuntu0.18.04.1, 1:68.2.2+build1-0ubuntu0.18.04.1), samba-libs:amd64 (2:4.7.6+dfsg~ubuntu-0ubuntu2.13, 2:4.7.6+dfsg~ubuntu-0ubuntu2.14), ros-melodic-rqt-gui-py:amd64 (0.5.0-0bionic.20191023.174058, 0.5.0-0bionic.20191205.000822), ros-melodic-desktop-full:amd64 (1.4.1-0bionic.20191109.020253, 1.4.1-0bionic.20191205.003555), ros-melodic-navigation:amd64 (1.16.2-0bionic.20191008.213836, 1.16.3-1bionic.20191120.172110), ros-melodic-rqt-moveit:amd64 (0.5.7-0bionic.20191023.174631, 0.5.7-0bionic.20191205.001840), ros-melodic-rqt-shell:amd64 (0.4.9-0bionic.20191023.174310, 0.4.9-0bionic.20191205.001338), ros-melodic-rqt-msg:amd64 (0.4.8-0bionic.20191023.174916, 0.4.8-0bionic.20191205.001912), ros-melodic-rqt-robot-monitor:amd64 (0.5.9-1bionic.20191023.174850, 0.5.9-1bionic.20191205.001820), thunderbird-locale-en-us:amd64 (1:68.2.1+build1-0ubuntu0.18.04.1, 1:68.2.2+build1-0ubuntu0.18.04.1), ros-melodic-rqt-reconfigure:amd64 (0.5.1-1bionic.20191105.194047, 0.5.1-1bionic.20191205.002105), ros-melodic-qt-gui:amd64 (0.3.15-1bionic.20191023.173351, 0.3.16-1bionic.20191204.235705), ros-melodic-fake-localization:amd64 (1.16.2-0bionic.20191008.202611, 1.16.3-1bionic.20191120.164538), ros-melodic-rqt-tf-tree:amd64 (0.6.0-0bionic.20191023.174653, 0.6.0-0bionic.20191205.002006), ros-melodic-rqt-py-common:amd64 (0.5.0-0bionic.20191023.173648, 0.5.0-0bionic.20191205.000338), ros-melodic-rqt-console:amd64 (0.4.8-0bionic.20191023.174626, 0.4.8-0bionic.20191205.001812), ros-melodic-navfn:amd64 (1.16.2-0bionic.20191008.211146, 1.16.3-1bionic.20191120.170557), ros-melodic-qt-gui-py-common:amd64 (0.3.15-1bionic.20191023.173319, 0.3.16-1bionic.20191204.235635), libssh-gcrypt-4:amd64 (0.8.0~20170825.94fa1e38-1ubuntu0.2, 0.8.0~20170825.94fa1e38-1ubuntu0.5), ros-melodic-rqt-srv:amd64 (0.4.8-0bionic.20191023.175154, 0.4.8-0bionic.20191205.002116), libsmbclient:amd64 (2:4.7.6+dfsg~ubuntu-0ubuntu2.13, 2:4.7.6+dfsg~ubuntu-0ubuntu2.14), ros-melodic-rqt-top:amd64 (0.4.8-0bionic.20191023.174239, 0.4.8-0bionic.20191205.001854), ros-melodic-rqt-pose-view:amd64 (0.5.8-0bionic.20191023.174351, 0.5.8-0bionic.20191205.001754), thunderbird:amd64 (1:68.2.1+build1-0ubuntu0.18.04.1, 1:68.2.2+build1-0ubuntu0.18.04.1), ros-melodic-urdf-sim-tutorial:amd64 (0.4.0-0bionic.20191023.174625, 0.4.0-0bionic.20191205.002035), ros-melodic-turtlebot3:amd64 (1.2.2-1bionic.20191008.220228, 1.2.2-1bionic.20191120.172521), ros-melodic-rqt-web:amd64 (0.4.8-0bionic.20191023.174225, 0.4.8-0bionic.20191205.001554), ros-melodic-rqt-graph:amd64 (0.4.10-0bionic.20191023.174317, 0.4.10-0bionic.20191205.001410), libpcap0.8:amd64 (1.8.1-6ubuntu1, 1.8.1-6ubuntu1.18.04.1), ros-melodic-nav-core:amd64 (1.16.2-0bionic.20191008.210203, 1.16.3-1bionic.20191120.170152), ros-melodic-urdf-tutorial:amd64 (0.4.0-0bionic.20191008.212339, 0.4.0-0bionic.20191125.141705), ros-melodic-amcl:amd64 (1.16.2-0bionic.20191008.202437, 1.16.3-1bionic.20191120.165340), ros-melodic-rviz-plugin-tutorials:amd64 (0.10.3-0bionic.20191008.212631, 0.10.3-0bionic.20191125.142721), ros-melodic-global-planner:amd64 (1.16.2-0bionic.20191008.212015, 1.16.3-1bionic.20191120.171037), ros-melodic-viz:amd64 (1.4.1-0bionic.20191105.200536, 1.4.1-0bionic.20191205.003437), ros-melodic-rqt-logger-level:amd64 (0.4.8-0bionic.20191023.174324, 0.4.8-0bionic.20191205.001717), ros-melodic-rqt-robot-plugins:amd64 (0.5.7-0bionic.20191023.175559, 0.5.7-0bionic.20191205.003305), ros-melodic-map-server:amd64 (1.16.2-0bionic.20191008.172315, 1.16.3-1bionic.20191120.164606), opera-stable:amd64 (65.0.3467.62, 65.0.3467.69), ros-melodic-qt-dotgraph:amd64 (0.3.15-1bionic.20191023.173328, 0.3.16-1bionic.20191205.000030), ros-melodic-rqt-nav-view:amd64 (0.5.7-0bionic.20191023.174934, 0.5.7-0bionic.20191205.001352), thunderbird-locale-en:amd64 (1:68.2.1+build1-0ubuntu0.18.04.1, 1:68.2.2+build1-0ubuntu0.18.04.1), ros-melodic-rqt-bag-plugins:amd64 (0.4.12-0bionic.20191023.175048, 0.4.12-0bionic.20191205.001834), ros-melodic-clear-costmap-recovery:amd64 (1.16.2-0bionic.20191008.211034, 1.16.3-1bionic.20191120.170605), ros-melodic-rqt-rviz:amd64 (0.6.0-0bionic.20191023.175438, 0.6.0-0bionic.20191205.002904), ros-melodic-move-base:amd64 (1.16.2-0bionic.20191008.212941, 1.16.3-1bionic.20191120.171702), ros-melodic-turtlebot3-navigation:amd64 (1.2.2-1bionic.20191008.215355, 1.2.2-1bionic.20191120.172146) End-Date: 2019-12-11 12:07:15