Third party apps not working on Fairphone OS 18.09.2

More than a year ago I bought a FairPhone2 because that's what a geek with social responsible inclinations (and some hardware hacking) does. It came with Android Marshmallow (aka 6), but last December I bit the bullet and upgraded to Nougat (7.1). Also, as any megacorporation paranoid geek would do, I don't have a Google account (even when 90%+ of my mails ends up in their humongous belly, but who uses mail nowadays anyways...), so I have been using it with F-Droid and Yalp Store.

The upgrade went smoothly, and almost right after it I was poking aroung the Yalp Store when I saw several system updates, including the Android System WebView. This component is the one responsible of showing web content in your apps, and, believe me, you use it more than you think. The new Android came with version 67.0.3396.87, and Yalp Store was offering v71.0.3578.99, so I didn't think about it and installed the further upgrade, along with most of the apps that I knew were not installed through F-Droid¹. There's also the fact that since Nougat, ASWB is deprecated in favor of embracing Chrome, but I have it disabled in my phone, just like most of the Google Apps (including Google Play Services).

The issue came when I tried to launch the official Selfoss reader. The list of articles worked fine, but trying to read one made the app crash. Even worse were the two homebanking apps I have: they didn't even show their main screen.

Thanks to a small troubleshooting session with jochensp in the #fairphone ICR channel, we found out that in fact it was a ASWB problem (hint: use adb logcat). Once more I had to use one of those don't-know-how-shady-it-is APK mirror sites (I used APKMirror, if you're curious, but don't blame me if the soft you install from there comes with all kinds of troyans).

The first thing I tried was to downgrade to the original version, so I downloaded the closest one I found (they didn't have the exact version, which makes me wonder how ofthen do they scan apps for upgrades), but downgrades don't work, even with adb install -r -d. For some reason, the same site offered a newer version than Yalp Store (72.0.3626.53, which I just found out it's a beta version!), so I upgraded (manual download + install) and that fixed it!