Version 2020.05-git-00560-gf3adc71b07 Hardware Handling / rtl8188eu, rtl8723bs and rtl8723bu are not building. The rest of the rtl* drivers are building fine. For rtl8188eu I have the compile error in os_dep / os_intfs.c:704:22 - looks like the wrong structure net_device is used. I use the standard kernel as per default in bananapi M1 configuration with glib and systemd, gcc 8.x.
The proper solution is mentioned in the build options of the rtl8188eu - enable WIRELESS_EXT for the kernel. So hier it is how you do it: make linux-menuconfig - activate kernel configuration Device Drivers \ Network device Support \ Wireless LAN \ Realtek devices This bug can be closed, it it not a bug.
Sorry, it was actually under Device Drivers \ Staging drivers \ Realtek RTL8188EU ...