View source for Windows/Build/emerge

''emerge'' is a tool to build the KDE sources and its third-party requirements on MS Windows. It is the '''easy''' way to build KDE on MS Windows.

== Introduction ==
Emerge is a tool that can build the different parts of KDE and its dependencies under Windows. We created this tool to automate and simplify the build process under Windows. We try to build all packages that we offer in the KDE installer with emerge. That has some advantages for us:
=== Easy for people to join us ===
Before emerge it was quite some work to set a system up for development. There were some quirks, which were documented in some mailing lists, but you had to remember them or you ran into an already solved problem again, etc.
Now to get a development machine you need a Windows computer, need to install Python and Git and do the emerge checkout. Then execute emerge to build what you want to build. This is easy for developers coming from Windows to KDE, and also for KDE developers coming to Windows.
=== Easy for us to do build ===
With emerge you can build the whole software stack (low-level libs, Qt, kdelibs, things above that) with only one command. You can start that build, and some hours later you can check if it worked, or if something broke. So we can spot problems easier and earlier. We can also start with a "naked" Windows computer without any other installed software and bootstrap kde on it. That ensures, that no hidden dependencies on some pieces of software sneak in, because then the builds on a "naked" computer would break and show the problem.
=== Easy to collaborate ===
We can test the same emerge build description for a package on different Windows versions/computers before we do binary releases. People can also add build descriptions for new packages to the Subversion repository.

This emerge tool was inspired by the Gentoo emerge tool.

== Set up the environment ==
=== Root directory ===
Create a directory if possible in your harddrive's root e.g. C:\kderoot or D:\kderoot (You will need this PATH later). This directory will contain the whole kde installation later. We will refer to it as KDEROOT.

=== Python interpreter ===
<tt>emerge.bat</tt> invokes an <tt>emerge.py</tt> script written in [http://en.wikipedia.org/wiki/Python_%28programming_language%29 Python] programming language, so you first need to [http://www.python.org/download/ install the Python 3.4 Interpreter]. The ''python'' installation directory will be added to the PATH later by <tt>KDEROOT\etc\kdesettings.ini</tt>.

=== Git client ===
The latest source code for Windows ''emerge'' and a lot of the rest of KDE is stored in a repository created and managed using the [http://git-scm.com/ Git] version control tool. You need a git client for the first checkout of emerge. There are at least two applications:
*a command line client, available at [http://code.google.com/p/msysgit/downloads/list?can=3 subversion.apache.org], aimed at developers or power users accustomed with the command line,
*a GUI program like [http://code.google.com/p/tortoisegit/ TortoiseGit], optional, useful for displaying differences between various versions of files in the repository in a graphical way.

Emerge uses its own git client for checking out all KDE source code. You can find it in KDEROOT\dev-utils\git\bin. It will be used by emerge even if you have another git executable installed.

=== Getting the ''emerge'' tool ===
The source code of the ''emerge'' tool and the recipes for creating KDE packages are located at <tt>git://anongit.kde.org/emerge.git</tt>, which is an URL based on the git-specific ''git'' protocol.

You need to clone the source code from the ''emerge'' git repository into a new directory below your root directory (the root directory is normally called %KDEROOT% here) or get it inside a self extracting archive (not tested yet).

==== Check out using the 'git' command ====

With the ''git'' command line tool, you can accomplish this with the following commands:
:: <pre>cd KDEROOT</pre>
*if you will only use anonymous (read-only) access to the KDE git repository:<pre>git clone git://anongit.kde.org/emerge.git</pre>
*if the git and ssh ports are blocked, and only http is allowed, it is better to clone over the http port for getting (read-only) access to the KDE git repository:<pre>git clone http://anongit.kde.org/emerge.git</pre>
*or, if you plan to use write access (commit) to the emerge repository using your existing account & OpenSSH private key: <pre>git clone git@git.kde.org:emerge.git</pre>

=== Configure the ''emerge'' tool ===
# Create the directory <tt>KDEROOT\etc</tt>.
# Copy the file <tt>KDEROOT\emerge\kdesettings.ini</tt> as <tt>KDEROOT\etc\kdesettings.ini</tt> and change its contents according to your needs.

Note 0: '''Read the comments in that file very carefully'''

Note 1: '''Be sure that you neither have the msys/bin nor the cygwin/bin in your path. If so you have to definitely remove it from the path.''' 

Note 2 '''from a user: The applications gimp, inkscape and graphviz are also a problem. To make sure that there's nothing wrong I stripped my path to contain only what I needed to build.'''

emerge has several branches which contain specific package versions. E.g. if you want to build the 4.13 branch of KDE (or one of the 4.13 releases) you should checkout the ''kde-4.13'' branch of emerge; in the ''master'' branch, you can find the KDE Frameweorks 5.

 To view all branches, use the following command:
<pre>git branch -a</pre>
To change the branch of emerge, do the following:
<pre>cd emerge && git checkout kde-4.13</pre>

=== [Optional, Advanced] emerge-boost-config.jam ===
Add a file emerge-boost-config.jam in the <tt>%KDEROOT%\etc</tt> directory to build boost in a specific way. The only current use case is for the following problem:
If you build 32bit binaries with emerge on a 64bit system you need to link boost-python against a 32bit python library. In case your standard python installation is 64bit though, you can specify the python installation in the following way:
<syntaxhighlight lang="text">
# ---------------------
# Python configuration.
# ---------------------

# Configure specific Python version.
using python : 3.2 : C:\\Python32_x86 ;
</syntaxhighlight>
This way boost-python would be using the headers & libraries from C:\\Python32_x86 instead of the default one.
Please remember that for mingw compilers you must regenerate the import library for the python dll (also for the mingw 64bit compiler):
<syntaxhighlight lang="text">
R:\> emerge pexports
R:\> pexports C:\Python32_x86\python32.dll > C:\Python32_x86\libs\python32.def
</syntaxhighlight>
NOTE: In case you generate the import library for the 64bit compiler, add the following line to the file python32.def:
<syntaxhighlight lang="text">
Py_InitModule4 = Py_InitModule4_64
</syntaxhighlight>
For both compilers you should now run:
<syntaxhighlight lang="text">
dlltool -d C:\Python32_x86\libs\python32.def -l C:\Python32_x86\libs\libpython32.dll.a
</syntaxhighlight>
Now you should be able to do emerge -i boost-python-src without errors.

== Using emerge ==

To use emerge you need to start a Powershell window and point that to <tt>KDEROOT\emerge</tt>. For example:

 C:
 cd KDEROOT\emerge

Then in the windows powershell you have to load the script with

 ". .\kdeenv.ps1"

This tells emerge about your environment settings (e.g. paths). It will load your configuration from <tt>KDEROOT\etc\kdesettings.ini</tt>. It should not give any error messages, otherwise emerge will not work as expected. The output should look similar to this one (of course with your paths):

 PS C:\kderoot\emerge>.\kdeenv.ps1
 KDEROOT     : r:\
 KDECOMPILER : mingw-w64
 KDESVNDIR   : s:\
 KDEGITDIR   : q:\
 DOWNLOADDIR : t:\
 PYTHONPATH  : C:\python34
 
 PS C:\kderoot\emerge>

''Note: There is a short path option in kdesettings which you will need if you want to build Qt in a directory that has a pathlength of more then around 5 characters. This problem is due to limitations of the command line length and the Qt build system.''

Next, if you have configured your kdesettings.ini to use svn+ssh for your subversion checkout, then you need to run:

<syntaxhighlight lang="text">plink <your-svn-username>@svn.kde.org
plink <your-kde-username>@git.kde.org</syntaxhighlight>

This will prompt you to accept the fingerprint of the server, otherwise svn will hang forever when trying to download from the server.

Now you should be able to use emerge. To get some help on usage:

 emerge --help

To get a list of available packages:
 emerge --print-installable

To get a list of currently installed packages:
 emerge --print-installed

== Setting up a compiler ==
Currently emerge supports both the MinGW and MS Visual C++ (msvc) compilers. We did not add dependencies for the compilers, so you have to make sure to install a compiler by yourself. There are three ways to set up a compiler for emerge.
We assumed you have set KDECOMPILER variable properly in the <tt>KDEROOT\etc\kdesettings.ini</tt>.

In the following sections you can find information on how to install or reuse an existing compiler.

=== Install the MinGW compiler with emerge ===
Let emerge install the MinGW compiler, as soon as emerge needs MinGW it will automatically fetch the correct version for you.

=== Install MS Visual C++ ===
Read [[../MS_Visual_Studio#The_Compiler|here]].

=== Point to an existing MS Visual C++ installation ===
You need to point emerge to an existing msvc installation. This is run automatically for you from kdeenv.bat if configured properly in kdesettings.ini. Check your kdesettings.ini file to know where to set it.

== Installing the base system ==
Once you have emerge and a compiler installed and working, try:

You are now ready to start building KDE, it is recommended to do so progressively, relying on emerge to automatically resolve the required dependencies at each set step:

* Enter <tt>emerge qt</tt>.  This will fetch and install Windows versions of numerous UNIX-like utilities and libraries, then checkout, compile and install Qt.  This will take several hours.
* Enter <tt>emerge frameworks</tt>.  This will checkout, compile and install the kde frameworks 5 modules.
* Enter <tt>emerge kde-baseapps</tt>. This will checkout, compile and install kdebase-runtime, and kdebase-apps.

You will now have successfully installed a base KDE system and can now install other KDE modules as required.

Note that this will install the development version of KDE (trunk in svn repositories, master in git repositories), if you wish to install a particular stable branch then you should change the branch of emerge to the specific branch of that release. '''NOTE:''' You should not mix kde packages from different branches.

It is strongly recommended you do not choose to manually install any of the utilities and libraries yourself, as you may install the wrong version and cause installation failures.  Instead allow emerge to resolve the dependencies for you.

Every time you want to update or install a package, you should first update your emerge checkout (simply run emerge --update emerge) to ensure you are using the latest package recipies.

== What emerge does ==
'''emerge ''packageName'' ''' performs the separate actions <tt>--fetch</tt>, <tt>--unpack</tt>, <tt>--compile</tt>, <tt>--install</tt>, and <tt>--qmerge</tt>.

The <tt>--fetch</tt> action will retrieve either a binary or the source code for the package:

== ''emerge'' command line options and settings ==
There are some options that can be used when building with ''emerge''.

{| border="0" cellpadding="2"
!Command line switch
!Command line argument
!
!Description
|-valign="top"
|<tt>-v</tt>
|<tt>EMERGE_VERBOSE</tt>
|width="5%"|
|This option sets the verbosity level. Currently the highest verbosity level is 3 (<tt>-v -v -v</tt>). A verbosity level of 0 should give no output and equals to <tt>-q</tt>. You can set <tt>EMERGE_VERBOSE=3</tt> instead in the environment of the commandline or within your <tt>kdesettings.ini</tt> file.
|-valign="top"
|<tt>--offline</tt>
|
|
|This option suppresses the update step of the local tree - which needs some time. Be aware though that you have to have existing sources already if you want to use this option.
|-valign="top"
|<tt>-t</tt>
|<tt>EMERGE_BUILDTESTS</tt>
|
|This option enables or disables KDE4 buildtests for KDE modules. Other packages will not change. Use <tt>EMERGE_BUILDTESTS=True</tt> or <tt>=False</tt>.
|-valign="top"
|<tt>--print-targets</tt>
|
|
|This option will display all "targets" a certain package has. Normally targets are fixed releases or different branches. They are defined in the portage file.
|-valign="top"
|<tt>--target=TARGET</tt>
|
|
|This sets a specific target for this package. If not added, the default target is used, which can be checked by looking at the output of '''--print-targets'''.
|-valign="top"
|<tt>-i</tt>
|
|
|This option ignores that a package is already installed. It builds it completely new, but keeps the dependencies.
|-valign="top"
|<tt>--update</tt>
|
|
|This option ignores that a package is already installed but doesn't cleanup an already existing build directory. Thus you will only rebuild files that have changed since the last build.
|}

== Hints ==
=== Updating packages ===
*Once you have ''packagename'' built, type <syntaxhighlight lang="text">emerge --update packagename</syntaxhighlight> to update <tt>packagename</tt> from the Subversion and compile it without removing the build dir or <syntaxhighlight lang="text">emerge --update-all</syntaxhighlight> to update all packages that can be rebuild (they are rebuild with --update).

=== General setup ===
For Fine Tuning see here:
[[Projects/KDE_on_Windows/Installation#Fine-tuning|Fine-tuning]]

==Vista issues==
*[[User:Jstaniek|jstaniek]] 12:02, 15 January 2008 (CET): UAC has infamous heuristics that make programs like patch.exe treat as installers and try to run them with admin rights (!). This heuristics can be tricked by renaming patch.exe to something like pch.exe ([http://nevali.net/2007/01/update-workaround-for-the-cygwin-uac-problem/ example]) but we did not want to add item to our infrastructure. Instead it is possibleto turn off the heuristics (see the screenshot [http://theinvisiblethings.blogspot.com/2007/02/running-vista-every-day.html here in the security blog calling the heuristics 'severe hole in the design of UAC']). If you happen to disable the UAC, as many annoyed users and devs do (msvc demands admin rights anyway!), patch.exe should already work for you as in older Windows. Alternatively you may want to disable UAC [http://www.howtogeek.com/howto/windows-vista/disable-user-account-controluac-for-administrators-only/ for admins only], but this makes no sense if you are the only user of your machine and use only the admin account.
* [http://ben.versionzero.org/wiki/Fixing_the_way_Vista_Auto-detects_Installers This wiki page] lists instructions on how to use program manifest to disable privilege elevation for a single binary and makes patch play nice with UAC.  This [https://bugs.kde.org/show_bug.cgi?id=186712 should] eventually be integrated to emerge scripts. 
 

[[Category:MS Windows]]