ember-cli: Unable to use Ember Leaflet with latest Ember CLI

Hello, all! I’m bringing this here from Discord at the suggestion of @rwjblue. A few weeks ago, I started a new Octane application (very exciting, by the way, thanks to everyone who’s worked so hard) and added Ember Leaflet with no trouble. This past weekend, I started a different application with a fresh Octane blueprint but when I tried to use Ember Leaflet, I got this error:

Could not find module `ember-leaflet/templates/leaflet-map` imported from `ember-leaflet/components/leaflet-map`

I suspected that the culprit would be one of the Ember-related projects in the package.json from the newest blueprint, so I substituted them with versions from my older application until the problem went away. I found that I was able to use Ember Leaflet as expected when I switched ember-cli from github:ember-cli/ember-cli#5bb062af85cebdf7dbc77132860dc2547fc7cfa4 to github:ember-cli/ember-cli#5c9bc9b4ef3d6ff5d886fff6f2d95f7373acc7e9.

You can see this reproduced with this example repository:

1. I added an acceptance test that looks for a string to be rendered in the application template and it passed.
2. After I added Ember Leaflet and inserted the map component before the searched-for string, the test failed.
3. When I changed to the older Ember CLI build, the test went back to passing.

@rwjblue suggested that it was #8633 that introduced this problem.

Let me know if I can provide any other details that might help!

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Output from ember version --verbose && npm --version && yarn --version:

ember-cli: 3.11.0-beta.3
http_parser: 2.8.0
node: 10.15.3
v8: 6.8.275.32-node.51
uv: 1.23.2
zlib: 1.2.11
ares: 1.15.0
modules: 64
nghttp2: 1.34.0
napi: 3
openssl: 1.1.0j
icu: 62.1
unicode: 11.0
cldr: 33.1
tz: 2018e
os: darwin x64
6.4.1
1.16.0