I know.
There's at least 3 raised topics so far.

However I am badly needing arp-scan.

According to all the resources online, this tool exists as a precompiled package in the repository.

However I was not able to find it for neither version of OpenWRT and for neither arch.

Moreover when I tried to configure it using the toolchain (for MIPS & x86), I've got tons of errors for missing libraries.
So far so good.

Tried to configure with the SDK: got error messages for missing libpcap_open_live support. The libpcap headers are in place... so there's no reason to complain.

Tried the buildroot as a last option. The package is totally missing from the feeds. Once I edit the feeds.conf like this:

src-git packages https://github.com/openwrt/packages.git

the package shows. However I am not able to compile it. The compile process just enters directory, then leaves it.

And that's all.

I'll be grateful if someone compile that one statically for x86 & MIPS. (I'll be running it on various platforms and OpenWRT versions)

Or at least give me step-by-step guide how to do it myself.

Thank you.