[Toybox] Android API 29 and custom Toybox upgrades

[Denys Nykula]

Hi Elliott, maintainers of Android apps with native executables are tweeting to
Rob but Android is your area of work so please comment:
https://twitter.com/topjohnwu/status/1171308880904646656

> I'm curious about @landley's (author of toybox) thoughts on the direction
> Android is heading. He had mentioned the goal to make Android fully self
> hosting, however ever since Android 10 it is not even possible to run
> downloaded executables if an app is targeting API 29.
> 
> Magisk Manager is hit by this restriction, and my current workaround is to
> simply target API 28. However someday in the future Google *will* eventually
> force all apps on Play Store to target 29 or higher, making apps such as
> @termux very hard to survive.
> 
> If even harmless apps like @termux that provides an isolated shell and a
> package manager aren't allowed, I think it's clear that making Android a self
> hosting platform is pretty much a pipe dream at this point.
> 
> P.S. I'm aware of the tool PRoot, however the technique it uses comes with
> significant overhead. It is fine in the case of running a few executables as
> in Magisk Manager, however I don't think it counts as a feasible solution for
> a so-called "self hosting platform".

What's new in API 29 for user's executables? If I adb shell and wget new builds
of Toybox and Dropbear, a) will they run in adb, b) will terminal emulators on
phone continue giving access to Android's builtin mksh and toybox and let me
run my own builds without root, c) will GNU/overlays such as Termux work that
give way to shell-scripting Android APIs for sound playback, camera etc?