Using latest freshly installed Armbian_21.05.1_Orangepipc2_buster_current_5.10.34, then went to armbian-config and installed kernel headers. There were no errors so I thought they now should be there, butl /usr/src is still empty.

There is also nothing in the system logs that would indicate an error in installing them.

Many thanks for any help.

In another forum post I found a hint to download the headers .deb file directly from

https://imola.armbian.com/apt/pool/main/l/

So I did that and installed it manually using

sudo dpkg -i linux-headers-current-sunxi64_21.05.1_arm64.deb

which worked. Strange that it didn't from armbian-config since I would think it does the same thing.