allenh1@hunter-laptop:~$ dpkg -l | grep colcon-cd
ii  python3-colcon-cd                                     0.1.1-1                                          all          A shell function for colcon to change the current working di

allenh1@hunter-laptop:~$ colcon_cd
colcon_cd: command not found
allenh1@hunter-laptop:~$ colcon --help
usage: /usr/bin/colcon [-h] [--log-base LOG_BASE] [--log-level LOG_LEVEL]
                       {build,extension-points,extensions,graph,info,list,metadata,test,test-result,version-check}
                       ...

optional arguments:
  -h, --help            show this help message and exit
  --log-base LOG_BASE   The base path for all log directories (default: ./log,
                        to disable: /dev/null)
  --log-level LOG_LEVEL
                        Set log level for the console output, either by
                        numeric or string value (default: warning)

colcon verbs:
  build                 Build a set of packages
  extension-points      List extension points
  extensions            List extensions
  graph                 Generate a visual representation of the dependency graph
  info                  Package information
  list                  List packages, optionally in topological ordering
  metadata              Manage metadata of packages
  test                  Test a set of packages
  test-result           Show the test results generated when testing a set of
                        packages
  version-check         Compare local package versions with PyPI

  {build,extension-points,extensions,graph,info,list,metadata,test,test-result,version-check}
                        call `colcon VERB -h` for specific help

Environment variables:
  CMAKE_COMMAND         The full path to the CMake executable
  COLCON_ALL_SHELLS     Flag to enable all shell extensions
  COLCON_COMPLETION_LOGFILE
                        Set the logfile for completion time
  COLCON_DEFAULTS_FILE  Set path to the yaml file containing the default values
                        for the command line arguments (default:
                        $COLCON_HOME/defaults.yaml)
  COLCON_DEFAULT_EXECUTOR
                        Select the default executor extension
  COLCON_EXTENSION_BLACKLIST
                        Blacklist extensions which should not be used
  COLCON_HOME           Set the configuration directory (default: ~/.colcon)
  COLCON_LOG_LEVEL      Set the log level (debug|10, info|20, warn|30,
                        error|40, critical|50, or any other positive numeric
                        value)
  COLCON_WARNINGS       Set the warnings filter similar to PYTHONWARNINGS
                        except that the module entry is implicitly set to
                        'colcon.*'
  CTEST_COMMAND         The full path to the CTest executable
  POWERSHELL_COMMAND    The full path to the PowerShell executable

allenh1@hunter-laptop:~$ ls ~/.local/lib/python3.6/site-packages/ | grep colcon
allenh1@hunter-laptop:~$ 

allenh1@hunter-laptop:~$ dpkg -L python3-colcon-cd
/.
/usr
/usr/lib
/usr/lib/python3
/usr/lib/python3/dist-packages
/usr/lib/python3/dist-packages/colcon_cd
/usr/lib/python3/dist-packages/colcon_cd/__init__.py
/usr/lib/python3/dist-packages/colcon_cd-0.1.1.egg-info
/usr/lib/python3/dist-packages/colcon_cd-0.1.1.egg-info/PKG-INFO
/usr/lib/python3/dist-packages/colcon_cd-0.1.1.egg-info/dependency_links.txt
/usr/lib/python3/dist-packages/colcon_cd-0.1.1.egg-info/entry_points.txt
/usr/lib/python3/dist-packages/colcon_cd-0.1.1.egg-info/requires.txt
/usr/lib/python3/dist-packages/colcon_cd-0.1.1.egg-info/top_level.txt
/usr/lib/python3/dist-packages/colcon_cd-0.1.1.egg-info/zip-safe
/usr/share
/usr/share/colcon_cd
/usr/share/colcon_cd/function
/usr/share/colcon_cd/function/colcon_cd.sh
/usr/share/doc
/usr/share/doc/python3-colcon-cd
/usr/share/doc/python3-colcon-cd/changelog.Debian.gz

allenh1@hunter-laptop:~$ export PATH="/usr/share/colcon_cd/function:${PATH}"
allenh1@hunter-laptop:~$ colcon_cd
colcon_cd: command not found
allenh1@hunter-laptop:~$ colcon_cd.sh
bash: /usr/share/colcon_cd/function/colcon_cd.sh: Permission denied

$ colcon cd my_package
              ...
colcon: error: argument verb_name: invalid choice: 'cd' (choose from 'alias', 'build', 'clean', 'extension-points', 'extensions', 'graph', 'info', 'list', 'metadata', 'mixin', 'test', 'test-result', 'version-check', 'clr')