[api-extractor] "ERROR: Internal Error: Unable to analyze the export" when using var #5507

Summary

I want to run api-extractor on a package interface which includes exported var values, which in d.ts manifest as
export declare var __name__: __type__

Repro steps

Minimal repro:
https://github.com/kuhe/tale-of-export-var-and-api-extractor

Expected result:

API extractor succeeds.

Actual result:

Error message:

ERROR: Internal Error: Unable to analyze the export "zero" in
/Users/***/workspace/tale-of-declare-var-and-api-extractor/lib/index.d.ts

You have encountered a software defect. Please consider reporting the issue to the maintainers of this application.

Details

Perhaps the initial reaction will be, like in #3353, that export var is not "recommended".
But I think that should not be up to this library, but rather the user. My team had started using api-extractor for documentation, and now find that we are unable to export vars, but unable to remove api-extractor as a dependency at the moment.

As a workaround, we will likely convert the vars into consts or lets, but shouldn't have to.

Standard questions

Please answer these questions to help us investigate your issue more quickly: