AX_BOOST_BASE and nix

Hi,

A few days ago I discovered msys2 and I am very pleased with the state of things overall.
My ultimate goal is to build nix from source inside msys2 on Windows 10.
Having nix on Windows would be a cornucopia, because it is very powerful build system.
I don't see potential in WSL, because it is just VirtualBox. It is not working if Windows inside VBox on Linux!

nix has lots of dependencies.
Some of them are already provided by msys2 through pacman.

My setup:

$ pacman -Syu
$ pacman -Su
$ pacman -S --needed base-devel mingw-w64-x86_64-toolchain
$ pacman -S pkg-config
$ pacman -S mingw-w64-x86_64-jq
$ pacman -S mingw-w64-x86_64-boost
$ git clone https://github.com/NixOS/nix
$ cd nix
$ ./configure
...
checking for lsof... lsof
checking for jq... /mingw64/bin/jq
./configure: line 5590: syntax error near unexpected token 1.66,' ./configure: line 5590: AX_BOOST_BASE(1.66, CXXFLAGS="$BOOST_CPPFLAGS $CXXFLAGS", AC_MSG_ERROR([Nix requires boost.]))'

I started reading autoconf and automake articles, but as for now the error message looks pretty cryptic to me and makes me think, that this is a parser error in m4.

Any hint would be helpful.

Start by reproducing the reported ./configure failure in the Nix source tree under MSYS2, focusing on the AX_BOOST_BASE call at configure line 5590 and the installed Boost package. Read the linked Nix build-from-source instructions and the MSYS2 setup commands; done means identifying whether the failure is caused by the environment or the build configuration and recording a reproducible resolution.