README: Mention that only MinGW-w64 works (but not MinGW).

diff --git a/README b/README
index 7666a5c144fe199d862410cfe4f6696d4d2eba68..4e2ba26e9f6f2fda88bd0e63d334930902e2732c 100644 (file)
--- a/README
+++ b/README
@@ -41,7 +41,13 @@ Building
 ========
 
 The package uses a GNU style build system and requires a Unix style shell.
-On Windows it can be built with the MinGW toolchain and MSYS environment.
+
+Windows builds can be created natively with the MinGW-w64 toolchain and
+MSYS environment, or cross-compiled using a MinGW-w64 toolchain:
+
+  http://mingw-w64.sourceforge.net/
+
+The "old" MinGW from http://mingw.org/ is not supported.
 
 Run "./autogen.sh" to generate the build system, "./configure" to setup, then
 "make" to build the library and "make install" to install it.