Throws error when using asar option

[okonet]

• I have read the contribution documentation for this project.
• I agree to follow the code of conduct that this project follows, as appropriate.
• I have searched the issue tracker for an issue that matches the one I want to file, without success.

Please describe your issue:

When setting asar as described in the documentation, running package command throws an error.

Console output when you run electron-forge with the environment variable DEBUG=electron-forge:*. (Instructions on how to do so here). Please include the stack trace if one exists.

An unhandled rejection has occurred inside Forge:
Cannot read property 'fail' of undefined
TypeError: Cannot read property 'fail' of undefined
    at /Users/okonet/Projects/codestage/node_modules/electron-forge/dist/api/package.js:259:23

What command line arguments are you passing?

none

What does your config.forge data in package.json look like?

{
      "make_targets": {
        "darwin": ["zip"]
      },
      "electronPackagerConfig": {
        "packageManager": "yarn",
        "icon": "resources/icon",
        "ignore": [".idea", "coverage"],
        "asar": {
          "unpack": "./src/electron/*.applescript",
          "unpackDir": "./src/electron/"
        }
      }
    }

Please provide either a failing minimal testcase (with a link to the code) or detailed steps to
reproduce your problem. Using electron-forge init is a good starting point, if that is not the
source of your problem.

Check out this commit: okonet/codestage@dd44eab and run y package

This is pointing to https://github.com/electron-userland/electron-forge/blob/v4.1.6/src/api/package.js#L142 so it seems packagerSpinner is undefined.