Overcoming softlock when creating /system/xbin on Android 9
actually all you need is place 3 files, no need to install anything
/data/adb/modules/busybox-ndk/module.prop
id=busybox-ndk
name=Busybox for Android NDK
version=1.31.1
versionCode=13115
author=osm0sis @ xda-developers
description=Static busybox binary for all Android architectures built with the NDK
support=https://forum.xda-developers.com/showthread.php?t=2239421

/data/adb/modules/busybox-ndk/service.sh
#!/system/bin/sh
/system/xbin/busybox --install -s /system/xbin

/data/adb/modules/busybox-ndk/system/xbin/busybox