It seems Android doesn't want an application to just quit on its own accord; after main() returns we need to kindly request Android to finish the activity and keep handling events until Android destroys the app.
The binary path we get from /proc/self/exe isn't very useful; the path to the .apk is barely more useful but it still doesn't make a whole lot of sense. It might make more sense to set it to the path of the native .so that is being loaded by NativeActivity.
These files are from the NDK, but don't seem to be included in termux. Since they are two small files that change very rarely, it's easier to just include them in the Panda repo.
[skip ci]
rdb
tobspr