--- pybind11-2.6.0/pybind11/setup_helpers.py.orig	2020-10-29 15:00:00.354647200 +0300
+++ pybind11-2.6.0/pybind11/setup_helpers.py	2020-10-29 15:03:00.504560300 +0300
@@ -46,6 +46,7 @@
 import tempfile
 import threading
 import warnings
+from sysconfig import _POSIX_BUILD
 
 try:
     from setuptools.command.build_ext import build_ext as _build_ext
@@ -58,7 +59,7 @@
 import distutils.ccompiler
 
 
-WIN = sys.platform.startswith("win32")
+WIN = sys.platform.startswith("win32") and not _POSIX_BUILD
 PY2 = sys.version_info[0] < 3
 MACOS = sys.platform.startswith("darwin")
 STD_TMPL = "/std:c++{}" if WIN else "-std=c++{}"
--- pybind11-2.6.0/setup.py.orig	2020-10-29 15:12:17.807830800 +0300
+++ pybind11-2.6.0/setup.py	2020-10-29 15:12:56.962339800 +0300
@@ -103,6 +103,7 @@
     with TemporaryDirectory() as tmpdir:
         cmd = ["cmake", "-S", ".", "-B", tmpdir] + [
             "-DCMAKE_INSTALL_PREFIX=pybind11",
+            "-G", "MSYS Makefiles",
             "-DBUILD_TESTING=OFF",
             "-DPYBIND11_NOPYTHON=ON",
         ]