Missing <sys/mman.h> on MSYS MinGW x64, Windows 7 (was missing Package libusb-1.0)

I am getting this error in msys2 when trying to compile stlink-tool

Package libusb-1.0 was not found in the pkg-config search path.
Perhaps you should add the directory containing `libusb-1.0.pc'
to the PKG_CONFIG_PATH environment variable
No package 'libusb-1.0' found

git clone https://github.com/jeanthom/stlink-tool
did not bring down the libusb folder

pkg-config was installed by pacman msys/pkg-config 0.29.2-4

I downloaded libusb-1.0.23.tar.bz2 from https://github.com/libusb/libusb/releases/tag/v1.0.23 but not clear to me what to do next to resolve this error.

Start with the MSYS2 build of stlink-tool and the reported pkg-config output. Check how the build locates libusb-1.0 and whether the MSYS MinGW x64 environment provides sys/mman.h. Done means the dependency is found and stlink-tool compiles on Windows 7.

Written by the indexing model from the issue text.