How to create a ROS snap correctly?

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I am following the tutorial at https://snapcraft.io/#ros to create a Ubuntu Snap from a ROS package on Github. This all goes well until running the snapcraftcommand, from https://snapcraft.io/first-snap/ros/l..., which results in the following error:

ERROR: no rosdep rule for 'roscpp_serialization'
Package 'roscpp_serialization' isn't a valid system dependency. Did you forget to add it to catkin-packages? If not, add the Ubuntu package containing it to stage-packages until you can get it into the rosdep database.

I'm assuming this means I should change something in the .yaml file but I am unsure exactly how this should look. Could anyone offer an example or any guidance?

Here's the .yaml file from the tutorial:

name: test-ros-talker-listener-test
 version: '0.1'
 summary: ROS Talker/Listener Example
 description: |
  This example launches a ROS talker and listener.
 confinement: devmode
 base: core18
 parts:
  ros-tutorials:
    plugin: catkin
    source: https://github.com/ros/ros_tutorials.git
    source-branch: melodic-devel
    source-space: roscpp_tutorials/

 apps:
  test-ros-talker-listener-test:
    command: roslaunch roscpp_tutorials talker_listener.launch