emerge is a tool to build the KDE sources and its third party requirements on MS Windows.
It automates much of the downloading, patching and compiling described in Getting Started/Build/Windows/GCC_And_MinGW
emerge.bat invokes an emerge.py script written in Python, so you first need to install the Python language.
The latest source code for Emerge and the rest of KDE is stored in a Subversion repository.
Check out the sources from the svn-directory of emerge into a new directory, which in this example we will call kderoot. If you have Subversion command-line tool, you can accomplish this with the following command:
svn co svn://anonsvn.kde.org/home/kde/trunk/kdesupport/kdewin32/emerge
Alternatively, you can checkout the sources using a program like TortoiseSVN.
Be sure to use a copy of Subversion that was built on Windows so that checked-out files do not use UNIX line endings. If you check out with UNIX line endings, the patch program will fail when attempting to apply a patch whose line endings don't match the system's.
Create the directory kderoot\etc. Copy the file kderoot\emerge\kdesettings-environment.bat to kderoot\etc\kdesettings.bat and change it according to your needs. Then run it.
emerge uses either the MinGW ("Minimalist GNU for Windows") GCC compiler and tools to build Qt and KDE from source code or on of the Microsoft Compilers (> Visual Studio 2003).
Currently, there is no dependency on the compilers in any of the packages. So, unless you call emerge mingw manually, have the compiler installed and in your path or alter the environment configuration scripts to add your existing MinGW bin directory to the PATH variable, compiling anything will choke. If you run emerge mingw, you will not need to modify the environment configuration scripts to point to a custom location.
If you see an error about cc1plus not being found, either add MinGW's \libexec\gcc\mingw32\3.4.5 to your PATH variable or copy the contents of this directory to MinGW's bin directory. The prior is preferred.
Everything applies to MS Visual Studio Compilers in a similar manner.
Start a console window and run
Check your path (run: echo %PATH%), it should have python and various directories within kderoot in it.
You can get 'some' help if you run:
Below the directory kderoot\emerge\portage are subdirectories for categories as subdirectories which contain the instructions for individual packages. The emerge script automatically handles package dependencies (except for the compiler, see #Compiling).
To build every required package for e.g. kdebase enter emerge kdebase. If you want to make a dry run, add the option -p to it.
Start with emerge qt and when that completes successfully, run emerge kdelibs.
emerge will fetch Windows versions of numerous UNIX-like utilities and libraries from the Internet, putting them in kderoot\bin, then get the Win32 support files, then Subversion, then Perl and the Qt libraries, etc.
Then emerge compiles the Qt libraries, this takes hours.
emerge is mostly usable together with the kdewin-installer but we're currently still working on some packages which are packaged in a wrong way. It is not recommended to use another layout then installer for directory_layout in the kdesettings.bat anymore (see that file for more detailed information).
emerge creates lots of files in \kderoot\tmp during build. After a package is successfully installed (check \kderoot\etc\portage\installed), you can delete its temporary directory.
emerge is derived from the Gentoo portage system, that has documentation for the portage format and emerge program.