bug#19989: 25.0.50; Build instructions on Windows

[Ilya Zakharevich <ilya@math.berkeley.edu>]

On Fri, Mar 06, 2015 at 10:21:49AM +0100, martin rudalics wrote:
> Setting up mingw without mingw-get from scratch (resolving all the
> necessary dependencies) looks like it could take at least a week here.
> Maybe I'm wrong but it appears that every DL and installation step has
> to be prepared carefully wrt overwriting (or not) previously installed
> libraries.
> 
> Using mingw-get (which I did) is complicated as well if you want to
> avoid falling into one of the traps mentioned in this thread.

I think building Emacs stole about 10 hours of my active time.
However, I must mention that the MAIN problem was:

  A) apparently, the download and build instructions changes not so
     long ago, so what google finds are obsolete irrelevant
     instructions.

  B) Since I got many different versions of Emacs build tree
     downloaded, I might have mixed up all the BAR/nt/INSTALL.  Do not
     know how did it happen EXACTLY, but for several rounds I was
     thinking I MUST run
        nt/configure.bat

The warning which nt/configure.bat gives is not specific enough (at
least when shown on background of all the [wrong] info found by googling):

echo ****************************************************************
echo *** THIS METHOD OF BUILDING EMACS IS NO LONGER SUPPORTED.     **
echo *** INSTEAD, FOLLOW THE INSTRUCTIONS FROM INSTALL.            **
echo ****************************************************************

--------------------------------------------

I cannot be sure, but I suspect that if it would show an extra line:

     **** The current way is to install MSYS and MINGW,          ****  
     ****    and run the top-level configure script.             ****

this might have saved me about half of these 10 hours.  (But it might
have been my very personal way to confuse myself, and this extra
message won’t be so useful for other people.) 

Ilya