Replicant

The website of http://android-rebuilds.beuc.net/ looks changed (as it now points to a gitlab instance).

In any case that project had (and probably still has) builds of the official Android SDK from the official Android source code.

The f-droid project is most probably already aware of it, so it could be nice to collaborate with f-droid to review that as they need an Android SDK to build applications¹.

• The android-rebuilds SDK is fully free
• No other nonfree software is needed to build Android applications with f-droid server

Then we might have a fully free toolchain to build Android application that is more recent than the Replicant 4.2 SDK.

As fdroidserver is already in Guix it might be easy enough to test that on existing FSDG distributions.

Nowadays Guix pack can even generate Debian packages and we even have documentation to construct tarballs with corresponding source code to code shipped with guix pack, so it could be relatively easy to enable FSDG distributions users to build Android applications. The SDK may requires an x86_64 computer as the Android build system now requires that.

Note that some applications could have nonfree dependencies because some of them probably use maven-central which has serious freedom issues , so we might only be able to build a subset of the applications with only free software.

The RepWifi might be a good candidate for testing as it was probably built with the Android 4.2 SDK, so it probably has no nonfree dependencies.

If we can build (some) applications this way, this could help a lot as we could then try to see if it's possible to build f-droid with only free software. In turn it could enable to modify f-droid to add support for filtering out non-fsdg compliant applications, at compilation time, and create f-droid metadata a recipe for building that f-droid version, and upstreaming everything. This way we'd have an FSDG compliant f-droid version maintained by upstream f-droid.

¹ For instance they state that they need an android SDK in their Installing the Server and Repo Tools documentation. Note that they are using the official SDK as published by google in this document, and that SDK is "under a proprietary license" according to that same document. So it might be useful to also collaborate on getting that documentation updated to promote free replacement for that nonfree SDK instead of pushing people to use nonfree software.