Frontend Development Setup Probems

Trying to setup a development environment to make some changes to the frontend.
I am using the configured docker containers for both the core and frontend git repositories.
Followed the instructions for setting up: Setup

When I add the following to configuration.yaml and restart:

frontend:
 development_repo:/workspaces/frontend/

It always comes up in safe mode.

In the log file I get:

2021-08-11 00:27:35 INFO (MainThread) [homeassistant.setup] Setup of domain ssdp took 0.0 seconds
2021-08-11 00:27:35 ERROR (MainThread) [homeassistant.setup] Unable to set up dependencies of default_config. Setup failed for dependencies: frontend, logbook, map, my
2021-08-11 00:27:35 ERROR (MainThread) [homeassistant.setup] Setup failed for default_config: Could not set up all dependencies.

Whether there is a space after development_repo:?