Documents the steps of building PostgreSQL on Windows Server 2012 64bit using MinGW (32bit builds as well as 64bit builds)

Postgres build on Windows Server 2012 using MinGW

Beware:
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If you wish to compile Postgres with XML support, tough luck! The libxml2 package that comes with MinGW/MSYS, named msys-libxml2, is rejected by gcc like this:

c:/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/4.7.0/../../../../x86_64-w64-mingw32/bin/ld.exe: skipping incompatible C:/MinGW/msys/1.0/lib/libxml2.a when searching for -lxml2

This is a known limitation as of now. Andrew Dunstan, the community buildfarm maintainer, as acknowledged this.

Make the environment bearable:
==============================

Download and install Fierfox from www.getfirefox.com

Download and install Sublime Text

Download and install 7zip.
	Launch it once, and Go to Tools > Options > 'Select All' (or pick your choices) > Apply/OK

Download and install Process Explorer

Download and install msysGit
	I used Git-1.8.0-preview20121022.exe from
	http://code.google.com/p/msysgit/downloads/list?q=full+installer+official+git
		(referred to by http://msysgit.github.com/)
	Choose to add only the Git binary to the PATH variable and not rest of the tools that come with msysGit.

Read:
=====
Read this doc if you want to figure out which package of MinGW-64w to download:
	http://sourceforge.net/apps/trac/mingw-w64/wiki/download%20filename%20structure

Download essentials:
===================

Latest mingw-w64-bin_i686-mingw from
	http://sourceforge.net/projects/mingw-w64/files/Toolchains%20targetting%20Win64/Automated%20Builds/

	I used: mingw-w64-bin_i686-mingw_20111220.zip

Latest mingw-get-inst-YYYMMDD.exe
	from http://sourceforge.net/projects/mingw/files/Installer/mingw-get-inst/

	I used: mingw-get-inst-20120426.exe

Latest ActivePerl from:
	from http://www.activestate.com/activeperl

	I used: ActivePerl-5.16.1.1601-MSWin32-x64-296175.msi

Latest Postgres Buildfarm scripts from:
	http://www.pgbuildfarm.org/downloads/releases/

    I used build-farm-4_9.tgz

Extract/Install:
================

Install mingw-get-inst-YYYYMMDD.exe
		Choose 'Prepackaged repository catalogues' (Mine listed: 20120426)
		Choose C:\MinGW as destination.
		De-select complete 'MinGW compiler suite' tree-node, since we'll be using the MinGW-64 binaries.
		Select only MSYS Basic system.
		Inspected the resulting log file to see that there were no errors.

Extract mingw-w64-bin_i686-mingw
	Exract mingw-w64-bin_i686-mingw_20111220.zip to C:\mingw64

For ease of running MSYS terminal, create a shortcut on Desktop that runs
	C:\MinGW\msys\1.0\msys.bat --norxvt

For keeping long screen output history, run the MSYS terminal from
	above created icon, and click on top-left corner of the window and go to
		Properties > Layout > 'Screen Buffer Size' > Height
	and set it to 9999 (max allowed).

Install bison, flex, patch, vim, perl, and m4.
	In the MSYS terminal, execute the following commands
		mingw-get install msys-bison
		mingw-get install msys-flex
		mingw-get install msys-patch
		mingw-get install msys-vim
		mingw-get install msys-perl
		mingw-get install msys-m4

	Remember, the msys-perl is needed for the build process, and the
		ActiveState perl (below) is used only to execute run_web_txn.pl script.

Install ActivePerl
	Execute the installer downloaded from ActiveState.com
	Choose the setting for the installer to change the PATH variable.

Extract Postgres Buildfarm sripts.
	In MSYS console, I extracted build-farm-4_9.tgz to ~/bf/

Create a mount point in MSYS, pointing to extracted C:\MinGW-w64\
==================================================================

    Edit /etc/fstab (C:\MinGW\msys\1.0\etc\fstab) to add this line:

    C:\mingw64\  /mingw-w64

    This mount point will be later used by buildfarm to build postgres using 64-bit toolchain.

Get Postgres sources:
=====================
    Use yor preferred method of getting a version of Postgres sources.

    I used Git to get the latest version (actually whole repository) of source code, like so:
		git clone git://git.postgresql.org/git/postgresql.git ~/POSTGRES

	This created Postres source code directory at ~/POSTGRES

Prepare buildfarm and Postgres sources:
=======================================
    Read this wiki page to get a better hang of build-farm:
		http://wiki.postgresql.org/wiki/PostgreSQL_Buildfarm_Howto

    Review and modify build-farm.conf file as necessary.

	I applied a patch to buildfarm scripts, available as a gist from
		https://gist.github.com/4455475

    Most important point in that patch is the fact that we use /mingw-w64/bin/ as a prefix of PATH env. variable.

Build Postgres:
===============

	Make a directory named root under ~/bf/
		mkdir ~/bf/root/
	(this is needed because the 'build_root' parameter in build-farm.conf
		has the value '/home/Administrator/bf/root') 

	From within the ~/bf/ directory, run the perl script to build Postgres:

	perl run_build.pl --verbose --from-source=/home/Administrator/POSTGRES HEAD