ember build does not show dead module stats?

here is my output:

$ ./run yarn build
yarn run v1.6.0
$ yarn ember build
$ EMBER_CLI_MODULE_UNIFICATION=true node_modules/.bin/ember build
DEPRECATION: ember-cli-babel 5.x has been deprecated. Please upgrade to at least ember-cli-babel 6.6. Version 5.2.8 located: emberclear -> ember-service-worker -> ember-cli-babel
DEPRECATION: ember-cli-babel 5.x has been deprecated. Please upgrade to at least ember-cli-babel 6.6. Version 5.2.8 located: emberclear -> lodash -> ember-cli-babel
DEPRECATION: ember-cli-babel 5.x has been deprecated. Please upgrade to at least ember-cli-babel 6.6. Version 5.2.8 located: emberclear -> ember-service-worker-asset-cache -> ember-cli-babel
Could not start watchman
Visit https://ember-cli.com/user-guide/#watchman for more info.
⠋ Building
---------------
environment:  development ENABLE_SW undefined
Service Worker Will Be Disabled:  true
---------------

DEPRECATION: ember-cli-babel 5.x has been deprecated. Please upgrade to at least ember-cli-babel 6.6. Version 5.2.8 located: /home/me/Development/NullVoxPopuli/emberclear/packages/frontend/node_modules/ember-service-worker/node_modules/ember-cli-babel
WARNING: ember-decorators (used in ember-bulma): You have not installed @ember-decorators/babel-transforms. It has been extracted to a separate addon. See instructions for installation: https://github.com/ember-decorators/babel-transforms#readme
src/services/intl.ts(1,25): error TS2307: Cannot find module 'ember-intl/services/intl'.
src/services/intl.ts(2,19): error TS2307: Cannot find module 'fetch'.
src/services/intl.ts(5,1): error TS6133: 'config' is declared but its value is never read.
src/services/intl.ts(5,20): error TS2307: Cannot find module 'emberclear/config/environment'.
src/services/intl.ts(18,10): error TS2551: Property 'addTranslations' does not exist on type 'EmberclearIntl'. Did you mean 'loadTranslations'?
src/services/intl.ts(22,30): error TS2339: Property 'localeWithDefault' does not exist on type 'EmberclearIntl'.
src/services/intl.ts(23,30): error TS2339: Property '_adapter' does not exist on type 'EmberclearIntl'.
src/services/intl.ts(26,35): error TS2339: Property '_owner' does not exist on type 'EmberclearIntl'.
src/ui/components/q-r-scanner/component.ts(54,21): error TS2351: Cannot use 'new' with an expression whose type lacks a call or construct signature.
src/ui/components/queue.ts(7,19): error TS7019: Rest parameter 'args' implicitly has an 'any[]' type.
src/ui/components/queue.ts(9,38): error TS2349: Cannot invoke an expression whose type lacks a call signature. Type 'never' has no compatible call signatures.
src/ui/components/queue.ts(13,35): error TS2345: Argument of type '(actions?: never[]) => (...args: any[]) => void' is not assignable to parameter of type '(params: any[], hash?: any) => any'.
  Types of parameters 'actions' and 'params' are incompatible.
    Type 'any[]' is not assignable to type 'never[] | undefined'.
      Type 'any[]' is not assignable to type 'never[]'.
        Type 'any' is not assignable to type 'never'.
src/ui/components/top-nav/user-drop-menu/add/add-modal/component.ts(32,10): error TS2339: Property 'close' does not exist on type 'AddModal'.
src/ui/components/top-nav/user-drop-menu/add/add-modal/component.ts(42,10): error TS2339: Property 'close' does not exist on type 'AddModal'.
src/ui/components/top-nav/user-drop-menu/invite/invite-modal/component.ts(33,32): error TS2345: Argument of type '{ promise: Promise<string>; }' is not assignable to parameter of type 'Partial<{ reason: any; isPending: boolean; isSettled: boolean; isRejected: boolean; isFulfilled: ...'.
  Type '{ promise: Promise<string>; }' is not assignable to type 'Partial<{ reason: any; isPending: boolean; isSettled: boolean; isRejected: boolean; isFulfilled: ...'.
    Types of property 'promise' are incompatible.
      Type 'Promise<string>' is not assignable to type 'Promise<any> | undefined'.
        Type 'Promise<string>' is not assignable to type 'Promise<any>'.
          Property 'new' is missing in type 'Promise<string>'.
src/ui/routes/application/route.ts(20,15): error TS2339: Property 'setLocale' does not exist on type 'EmberclearIntl'.
src/ui/routes/settings/controller.ts(2,18): error TS6133: 'computed' is declared but its value is never read.
cleaning up...
Built project successfully. Stored in "dist/".
Done in 24.64s.

(most of this is type warnings)

the readme says I should see something like:

ember build
...
dead 115
traversed 2935

after adding

    treeShaking: {
      enabled: true
    }

to my ember-cli-build.js file.

kellyselden / ember-cli-tree-shaker

ember build does not show dead module stats? #47