ember-test-waiters v2 upgrade causes this to break?

[NullVoxPopuli]

Looks like an update to ember-test-waiters (v2) causes this lib to break?
C.I. run: https://github.com/NullVoxPopuli/emberclear/pull/558/checks?check_run_id=476263612
Error:

not ok 1 Chrome 80.0 - [191 ms] - Acceptance | Settings | Relays > when logged in: the default relays are rendered
    ---
        actual: >
            null
        stack: >
            TypeError: Cannot read property 'TestWaiter' of undefined
                at Object.get [as TestWaiter] (https://0.0.0.0:7357/assets/vendor.js:101768:21)
                at reset (https://0.0.0.0:7357/assets/vendor.js:91619:45)

Project Search:

Not sure why -- but wanted to report it in case this hasn't been reported yet or someone can point out I'm being stupid ;)

---

Debugging further,
running locally, (in firefox):

the error is that _types is undefined?

oh dang, this is in ember-test-waiters.....

weeeeiiiird
ok, well, chrome is reporting the same error, but with a less helpful error message.

Debugging the stack trace:

looks like that is in ember-app-scheduler/scheduler?
never heard of this package.

anywho, I no longer think this is an issue with ember-concurrency-test-waiter, so I'll move to ember-test-waiters