Android apps ship with a file called AndroidManifest.xml that (among other things) tells the operating system the latest version of the API that the app understands, i.e. what the app was compiled and tested against. The operating system tries to maintain backward compatibility with what the app is expecting.

The Termux maintainers have built their app to tell the operating system that Termux is only aware of how the Android 9 API works. So when you run Termux on your Android 10 device, the operating system tries to behave like it's Android 9. So it allows this.

They (Google) do this to ease the transition so that when a new version of Android is released, they don't force all developers everywhere to immediately fix all compatibility issues.

But they do want developers to do it eventually, so at some point in the future, they will probably stop allowing the Termux maintainers to upload an app that declares "I don't understand Android 10 yet".

> I'm confused, because I use termux on android-10 (on a pixel2) without any problem.

It's only an issue if applications target Android 10 APIs. Termux still targets an older API version and is thus not yet affected by this issue. Eventually they'll need to target a newer version because the Google Play store specifies a minimum API version that applications need to use.

Android apps specify a target SDK version (essentially a kind of OS version) in their manifest alongside a min SDK version. The advantage of targeting a newer SDK than the oldest one you support is that you get access to new APIs, but it often comes with additional restrictions as well. Google Play periodically updates their policy to require that targetSdkVersion be above a certain value in order for an app to be published in the play store (currently that value corresponds to Android 9) [1]. What this means is that this policy is an optional trade-off today but likely to be a requirement in the future.

[1]: https://developer.android.com/distribute/best-practices/deve...

You are running in a compatibility mode. If they built it declaring support for Android 10 at build time it would be subject to the new rules and break.

Long term, I can only assume targeting an old SDK will not be supported at some point.

> I have a cron running on it that mails my notifications to me.

Off-topic, but that's awesome! How do you get access to your notifications from Termux?

Termux exposes an api as binaries, putting them in `$PATH`, so you can then call them in a any script/program: https://wiki.termux.com/wiki/Termux:API

It basically give access to most permissions an app can get. The cool thing is that you allow the permission for termux, and then all you scripts can use them.

But yeah indeed, the notif2mail was quite a game changer, for me :) I had a big problem of spam calls/sms at some point, and this allowed me to get my notifications through my spam filter and remove the spam. I also use it to trigger desktop notification when my phone battery is low or full.

EDIT: oh, actually, it's not termux itself, but the addon Termux:API (which is a second app, from Play Store point of view). Also, the command to list notifications is `termux-notification-list`, but it doesn't appear in this documentation page, for some reason. All api executable start with `termux-`, so it's quite easy to list them from the shell.

To start cron when booting the phone, I had also to use an other addon, Termux:Boot : https://wiki.termux.com/wiki/Termux:Boot