This topic is as a side note that OpenWRT build System Setup for WSL enviroment.

How to OpenWRT Build system setup WSL is placed on webpage by the OpenWRT org.

https://openwrt.org/docs/guide-developer/toolchain/wsl

Building Eiviroment

WSL:

Ubuntu 22.04.3 LTS (GNU/Linux 5.15.90.1-microsoft-standard-WSL2 x86_64)

How to Build OpenWRT on WSL

Installing packages for building

sudo apt update
sudo apt upgrade
sudo apt install build-essential clang flex bison g++ gawk \
gcc-multilib g++-multilib gettext git libncurses-dev \
libssl-dev python3-distutils rsync unzip zlib1g-dev file wget

making folder

Allowing permissions of folder using Windows OS folder property.

• Open target foleder property
• Select [Security] tab
• Select Users from list of Goup or usr names , and Press [Edit] button
• Allow permissions [Full control], [Modify]

Enabling CaseSensitivity of the created folder

fsutil.exe file setCaseSensitiveInfo <folder path> enable

Getting built soruce code using git clone or wget in the targe folder

example)
git clone https://github.com/openwrt/openwrt -b v23.05.0

System Target setting using menuconfig

make menuconfig
* setting any system target 

Building using Temporary Enviroment path

PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin make

OpenWRT firmwares building is completed !