Running AngularDart in docker container - memory use - docker

Question

I am running an AngularDart project in a Docker Container google/dart and install webdev.
It is running very slow, so I have tried to add more cpu - do you know how to optimise and make it faster and is it good practice to run AngularDart in google/dart?
docker container run --name webdev -it --rm -p 8080:8080 -v $(pwd):/usr/src/app --cpu-shares=2 google/dart
The first time, it builds ok, but after making changes - the second build is very slow.
You can see the build log here:
webdev serve --hostname 0.0.0.0
Creating build script, took 22350ms
[INFO] Setting up file watchers completed, took 135ms
[INFO] Waiting for all file watchers to be ready completed, took 5.6s
[INFO] Reading cached asset graph completed, took 2.9s
[INFO] Checking for updates since last build completed, took 4.3s
[INFO] Running build completed, took 1.9s
[INFO] Caching finalized dependency graph completed, took 1.5s
[INFO] Succeeded after 3.5s with 0 outputs (0 actions)
Serving `web` on http://0.0.0.0:8080
Serving `test` on http://0.0.0.0:8081
[INFO] ------------------------------------------------------------------------
[INFO] Starting Build
[INFO] Updating asset graph completed, took 57ms
[WARNING] No actions completed for 32.6s, waiting on:
- angular on lib/app_component.dart
[WARNING] No actions completed for 15.0s, waiting on:
- build_web_compilers|ddc on lib/app_component.template.dartdevc.module
[WARNING] No actions completed for 15.1s, waiting on:
- build_web_compilers|ddc on lib/app_component.template.dartdevc.module
[WARNING] No actions completed for 20.6s, waiting on:
- build_modules|dartdevc on lib/app_component.template.dartdevc.module
[WARNING] No actions completed for 31.2s, waiting on:
- build_modules|dartdevc on lib/app_component.template.dartdevc.module
[INFO] Running build completed, took 2m 28s
[INFO] Caching finalized dependency graph completed, took 3.1s
[INFO] Succeeded after 2m 31s with 12 outputs (10 actions)