Ref for electron-builder/general "other stuff Apple wants you to do when notarizing": https://kilianvalkhof.com/2019/electron/notarizing-your-electron-application/

I'd be happy to get an in-detail guide started (or if anyone feels like it, they're welcome to plagiarize use any part of the article.)

Thank you Kilian for the walkthrough. This is one of those rare blogposts that are immediately comprehensive, instructive and (almost) error-free (there is a } to many in the afterSign script you provide IIRC).

An in-depth guide would certainly be helpful, but the post is already sufficient to implement this in 15 minutes. And then, of course, wait another 15 minutes for the Apple API to grace you with a working ticket.

(there is a } to many in the afterSign script you provide IIRC).

Cheers, fixed!

We're trying to reproduce getting a security warning with a signed app - either in mojave or the catalina beta - and even though the app is signed after 1st June and not notarized, we are not getting blocked or seeing additional warnings other than the (you downloaded this from the internet). we are using a dmg.

Has anyone seen this affect an electron app or have more info about how to reproduce the blocking?

We eventually reproduced by allowing the beta to update itself to the latest beta. Our developer account fits that criteria and our app is blocked. Thanks for the suggestion.

With two last Catalina betas we started to have some notarization or signing problems here
AdguardTeam/AdGuardForSafari#172
and as it mentioned in the issue, there are same problems even with Whatsapp.

So I guess, the notarization requirement is in full effect already.