nt/INSTALL: More details about creating the build environment.

nt/INSTALL

@@ -238,6 +238,16 @@ Windows 9X as well).
   install the packages manually, we recommend to use the Windows port
   of the 'bsdtar' program, already mentioned above.
 
+  MSYS packages should be installed in a separate tree from MinGW.
+  For example, use D:\MSYS or D:\usr\MSYS as the top-level directory
+  from which you unpack all of the MSYS packages.
+
+  After installing Automake and Autoconf, make sure any of the *.m4
+  files you might have in your MinGW installation (e.g., pkg.m4 that
+  comes with pkg-config) also exist in the MSYS installation tree, in
+  the share/aclocal directory.  Those *.m4 files which exist in the
+  MinGW tree, but not in the MSYS tree should be copied there.
+
   If/when you are confident in your MinGW/MSYS installation, and want
   to speed up the builds, we recommend installing a pre-release
   version of Make from here:
@@ -265,10 +275,6 @@ Windows 9X as well).
   states the missing or incompatible DLL; be sure to find and install
   these missing DLLs.
 
-  MSYS packages should be installed in a separate tree from MinGW.
-  For example, use D:\MSYS or D:\usr\MSYS as the top-level directory
-  from which you unpack all of the MSYS packages.
-
   Do NOT add the MSYS bin directory to your Windows Path!  Only the
   MinGW bin directory should be on Path.  When you install MSYS, it
   creates a shortcut on your desktop that invokes the MSYS Bash shell
@@ -305,6 +311,10 @@ Windows 9X as well).
      ok
      Checking for automake (need at least version 1.11)...
      ok
+     Checking for pkg-config (need at least version 0.9.0)...
+     ok
+     Checking for pkg.m4...
+     ok
      Your system has the required tools, running autoreconf...
      You can now run `./configure'.