"/lib/modules/<kernel version>/build: No such file or directory" when executing "make"

[Urb1101]

No description provided.

[jlinktu]

#441
#615

[Urb1101]

I am going to install nexmon with raspberry pi 4B, but I encountered error like the issue title when executing this point↓
https://github.com/seemoo-lab/nexmon#:~:text=bcm43436b0/9_88_4_65/nexmon/-,Compile%20a%20patched%20firmware%3A%20make,-Generate%20a%20backup
and checked "/lib/modules/" but couldnt find /build.
I used "rpi-update" command to downgrade kernel so which maybe cause missing /build.
my kernel viersion is 5.10.73-v8+ but i couldnt find linux-headers-5.10.73-v8+.(I used "sudo apt-get install ～)
there is way to install kernel header for this version or other way to solve this error?
sorry for my bad english.

[Urb1101]

#441 #615
thank you for fast reply.
#441 didnt work for me, i dont know #615 is good for me. at least I couldnt got something to solve this issue.

[jlinktu]

There are plenty of resources online that describe how to install kernel headers on Raspberry Pi OS, please consult the search engine of your choice to solve that.