colcon build ros1_bridge not producing executable

edit

UPDATE: my original question was about colcon build parameters, but thanks to the answer I discovered that the problem was not there. Hence I have adjusted a little bit the question for future reference.

Hi,

I'm basically following the ROS2 official documentation for installing from sources (reference here).

When I build the workspace using

colcon build

It looks like ros1_bridge executables are not installed.

If I source everything using

source install/setup.zsh

The output of ros2 pkg list shows ros1_bridge, but, checking ros2 pkg executables there are no executables.

I have the following directory

.ros2_ws/install/ros1_bridge
  |_ include
  |_ lib
     |_ libros1_bridge.so
     |_ python3.5
     |_ ros1_bridge
        |_ EXECUTABLES should be here but are not present.
  |_ share

Do you know why?