Invoking "make cmake_check_build_system" failed

[Paul Santos]

I had a problem when i was in this step

Clone this repository into your catkin workspace, install the dependencies and build it:

cd ~/catkin_ws/src/
git clone https://github.com/code-iai/iai_kinect2.git
cd iai_kinect2
rosdep install -r --from-paths .
cd ~/catkin_ws
catkin_make -DCMAKE_BUILD_TYPE="Release"

when I launched this part : catkin_make -DCMAKE_BUILD_TYPE="Release"
the output was:

Base path: /home/paul/catkin_ws
Source space: /home/paul/catkin_ws/src
Build space: /home/paul/catkin_ws/build
Devel space: /home/paul/catkin_ws/devel
Install space: /home/paul/catkin_ws/install

Running command: "make cmake_check_build_system" in "/home/paul/catkin_ws/build"

-- Using CATKIN_DEVEL_PREFIX: /home/paul/catkin_ws/devel
-- Using CMAKE_PREFIX_PATH: /opt/ros/melodic
-- This workspace overlays: /opt/ros/melodic
-- Found PythonInterp: /usr/bin/python3 (found suitable version "3.6.8", minimum required is "2")
-- Using PYTHON_EXECUTABLE: /usr/bin/python3
-- Using Debian Python package layout
-- Using empy: /usr/bin/empy
-- Using CATKIN_ENABLE_TESTING: ON
-- Call enable_testing()
-- Using CATKIN_TEST_RESULTS_DIR: /home/paul/catkin_ws/build/test_results
-- Found gmock sources under '/usr/src/googletest': gmock will be built
-- Found PythonInterp: /usr/bin/python3 (found version "3.6.8")
-- Found gtest sources under '/usr/src/googletest': gtests will be built
-- Using Python nosetests: /usr/bin/nosetests-2.7
ImportError: "from catkin_pkg.package import parse_package" failed: No module named 'catkin_pkg'
Make sure that you have installed "catkin_pkg", it is up to date and on the PYTHONPATH.
CMake Error at /opt/ros/melodic/share/catkin/cmake/safe_execute_process.cmake:11 (message):
execute_process(/usr/bin/python3
"/opt/ros/melodic/share/catkin/cmake/parse_package_xml.py"
"/opt/ros/melodic/share/catkin/cmake/../package.xml"
"/home/paul/catkin_ws/build/catkin/catkin_generated/version/package.cmake")
returned error code 1
Call Stack (most recent call first):
/opt/ros/melodic/share/catkin/cmake/catkin_package_xml.cmake:74 (safe_execute_process)
/opt/ros/melodic/share/catkin/cmake/all.cmake:167 (_catkin_package_xml)
/opt/ros/melodic/share/catkin/cmake/catkinConfig.cmake:20 (include)
CMakeLists.txt:56 (find_package)

-- Configuring incomplete, errors occurred!
See also "/home/paul/catkin_ws/build/CMakeFiles/CMakeOutput.log".
See also "/home/paul/catkin_ws/build/CMakeFiles/CMakeError.log".
Makefile:320: recipe for target 'cmake_check_build_system' failed
make: *** [cmake_check_build_system] Error 1
Invoking "make cmake_check_build_system" failed