@relan Thanks for testing.
Yes, API31 seems to require JDK11.
I updated OpenTracks’ CI to use JDK11 and now this PR passes.
Do you have a timeline for this?
EDIT: Branch is updated to include JDK11 for CI: [Wait for F-Droid's support of JDK11] Upgrade to API level 31 (Android12). by dennisguse · Pull Request #884 · OpenTracksApp/OpenTracks · GitHub