Sourcemaps + fingerprinting regression with ember-cli-terser 4.0.2?

The combination of ember-cli-terser 4.0.2, sourcemaps, and asset fingerprinting with the prepend option seems broken. It works with 4.0.1.

The generated sourcemap just has a single file in its "arrays" property. Eg: `{ "sources":["assets/app-24b6516628ce0829b2e18e768cd8ce2b.js"] `, instead of the full list of source files you'd expect.

It appears to work correctly if the fingerprint.prepend option is removed.

May be caused by one of these:

https://github.com/ember-cli/ember-cli-terser/commit/97cef3cab6f912da920f7eeaa8f21e01ca78268b
https://github.com/ember-cli/ember-cli-terser/commit/8279c890739388c35ff467cf5cc1d68951a9bdd4

Is this a known problem? I've downgraded to 4.0.1 for now.