Angular 8 Builds Hanging Upon Completion

I’m running into an issue where Angular 8 builds are hanging in Concourse. This is only happening in Angular 8, and only in Concourse. The build appears to complete from the output (I’m using --verbose and comparing progress). Concourse remains stuck on from the build command at the end.

Concourse v5.4.1
Angular 8.2
Brand new angular app generated with the CLI.
(Task below)

Hijacking into the container, I can see the ng build process is still running (via top), but it’s not using any CPU. I can also run the build via with fly execute, same behavior.

Any suggestions how to debug further, or what might be wrong?

Task:

platform: linux
image_resource:
  type: docker-image
  source:
    repository: node
    tag: 11.12
inputs:
  - name: source
outputs:
  - name: dist
run:
  path: sh
  args:
  - -exc
  - |
    eval "export NG_CLI_ANALYTICS=ci"
    eval "echo \"$NG_CLI_ANALYTICS\""
    cd "source/myApp"
    eval "npm install"
    eval "./node_modules/.bin/ng build --verbose"
    
    cd -
    mv source/myApp/dist/* dist/