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colcon silently does nothing

asked 2019-11-14 09:50:43 -0600

gdebrecz gravatar image

updated 2019-11-14 12:01:56 -0600

gvdhoorn gravatar image

Hi !


  • Ubuntu 18.04
  • I installed ROS Eloquant
  • Followed this tutorial:
  • Everything was ok, until I reached the colcon build command.
  • It was doing nothing, and gave no error, no message, verbose output was:

    $ colcon --log-level 10 build
    DEBUG:colcon:Parsed command line arguments: Namespace(build_base='build', continue_on_error=False, event_handlers=None, executor='sequential', install_base='install', log_base='log', log_level=10, main=<bound method BuildVerb.main of < object at 0x7f8dc26f30b8>>, merge_install=False, paths='.', symlink_install=False, test_result_base=None, verb_extension=< object at 0x7f8dc26f30b8>, verb_name='build', verb_parser=CustomArgumentParser(prog='/usr/bin/colcon build', usage=None, description='Build a set of packages.', formatter_class=<class 'colcon_core.command.CustomFormatter'>, conflict_handler='error', add_help=True))
    INFO:colcon.colcon_core.location:Using log path 'log/build_2019-11-14_16-30-55'
    [0.089s] INFO:colcon.colcon_core.executor:Executing jobs using 'sequential' executor
    [0.090s] DEBUG:colcon.colcon_core.executor.sequential:closing loop
    [0.090s] DEBUG:colcon.colcon_core.executor.sequential:loop closed
    [0.090s] DEBUG:colcon.colcon_core.event_reactor:joining thread
    [0.090s] DEBUG:colcon.colcon_core.event_reactor:joined thread
    [0.093s] INFO:colcon.colcon_core.plugin_system:Skipping extension '': Not used on non-Windows systems
    [0.093s] prefix script '/home/gdebrecz/works/dev_ws/install/'
    [0.094s] prefix util module '/home/gdebrecz/works/dev_ws/install/'
    [0.095s] prefix chain script '/home/gdebrecz/works/dev_ws/install/'
    $ echo $?

with no error. ROS package was not build. What am I doing wrong ? thanks, G

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The fact that it uses the sequential executor indicates that you might not have installed all recommended colcon packages . Specifically colcon-parallel-executor seems to be missing. Can you share the output of dpkg -l | grep colcon.

Dirk Thomas gravatar image Dirk Thomas  ( 2019-11-14 10:12:01 -0600 )edit

Hi ! Thanks for the answer ! Your command returns with:

ii python3-colcon-core 0.4.3-1 all Command line tool to build sets of software packages.

Howevere, I followed the official ROS install guide and found no mention of need of installing other colcone packages. thanks, g

gdebrecz gravatar image gdebrecz  ( 2019-11-14 14:39:14 -0600 )edit

Can you please post a link which instructions you followed.

Dirk Thomas gravatar image Dirk Thomas  ( 2019-11-14 15:25:20 -0600 )edit

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answered 2019-11-14 15:27:25 -0600

tfoote gravatar image

For that tutorial, a prerequisite is Creating a workspace and for that tutorial a prerequisite is colcon installation Which tells you to install python3-colcon-common-extensions

You don't clarify which installation instructions you followed. I suspect that you installed prebuilt binaries that don't need the build tools to run. There are different instructions for how to install ROS 2 to be able to run, versus being able to build.

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Thanks a lot for the help and pointers ! Indeed, I've overlooked that bad, sorry. After redoing the complete exercise everything works. Thanks again !

gdebrecz gravatar image gdebrecz  ( 2019-11-19 07:08:49 -0600 )edit

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Asked: 2019-11-14 09:50:43 -0600

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Last updated: Nov 14 '19