Hackable Mercurial for Windows

An approach to easily hack on the Mercurial source on Windows.

1. What is the Hackable package?

Compiling Mercurial is a significant barrier to testing and developing Mercurial on Windows. This package attempts to minimize that barrier by including:

• a private copy of Python (32-bit)
• complete Mercurial history
• pre-compiled extensions (32-bit MinGW GCC)
• an hg.exe wrapper to add to your path
• in-place editable source checked out and ready to go

2. Downloading and using

The package can be found here. Simply download, unzip, and run the included hg.exe. This package will not interfere with your existing Mercurial or Python installation.

There is usually no need to download new copies between releases, simply pull and update.

This package includes no global configuration, so if you're not already using Mercurial, you will need to configure your username and merge tools.

3. How it's built and how to build your own from scratch

Needed components:

• Python MSI installer, versions 2.4 - 2.7

• Mercurial source release (see Download)

• MinGW mingw-get tool

• The exemaker launcher (binary available here)

Steps:

• Download all the needed components

• Install Python with msiexec /i python-2.6.6.msi /qb

• Unpack the mingw-get tool into c:\MinGW and add c:\MinGW\bin to your path

• Install the gcc compiler with mingw-get gcc

• Unpack Mercurial source into c:\hg

• Copy the Python install from c:\Python26 to c:\hg\hg-python26

• Edit c:\hg\hg-python26\Lib\distutils\cygwinccompiler.py to remove all references to -mno-cygwin (thanks, GCC!)

• Build Mercurial extensions in c:\hg with hg-python26\python setup.py build_ext -i --compiler=mingw32

• Copy the c:\hg\hg to c:\hg\hg.py and change the #! line to '#!hg-python/python.exe'

• Unpack exemaker and copy exemaker.exe to c:\hg\hg.exe

4. Running the test suite under MSYS

Most of the test suite can now be run on windows too. Writing tests and debugging failures might however require both knowledge of the traditional unix environment and of the windows environment.

The tests that can’t be run on windows will automatically be skipped, so no test failures should be seen. It is not acceptable that so many tests are skipped - please improve that. Nobody is running the tests regularly, so it is very positive that you will see some false negatives.

Creating a hg-winhack package and running the test suite requires almost the same environment. The following instructions will thus contain a lot of duplication of the instructions given above, and the instructions could perhaps be merged. (The “hackable” mentioned above might not work in development branches.)

4.1. Install MinGW/MSYS environment

• Install MinGW/MSYS with 'mingw-get-inst-*.exe' from http://sourceforge.net/projects/mingw/files/latest/download

• Install some mandatory extra packages: c:\MinGW\bin\mingw-get install msys-base msys-coreutils gcc

• Install some optional extra packages: c:\MinGW\bin\mingw-get install msys-rxvt msys-vim msys-wget msys-unzip msys-zip msys-openssh

• Launch a console/terminal with: c:\MinGW\msys\1.0\msys.bat --rxvt and enjoy having a decent shell

• Put 'c:/MinGW/bin' in '$PATH' ... or 'mount c:/MinGW /mingw'

4.2. Build hg-winhack

# create build directory
hg clone http://selenic.com/hg hg-winhack   # bootstrap Mercurial somehow
cd hg-winhack
# install python
wget http://python.org/ftp/python/2.7.2/python-2.7.2.msi
msiexec //i python-2.7.2.msi //qb   # avoid MSYS magic mangling of '/i'
cp -ar c:/Python27 hg-python27   # python can and should now be uninstalled again
sed -i 's,-mno-cygwin, ,g' hg-python27/Lib/distutils/cygwinccompiler.py
# build Mercurial extensions
hg-python27/python setup.py build_ext -i --compiler=mingw32
# create hg.exe launcher
sed 's,^#!/usr/bin/env python,#!hg-python27/python27.dll,g' hg > hg.py
rm hg
wget http://effbot.org/media/downloads/exemaker-1.2-20041012.zip -O exemaker.zip
unzip -j exemaker.zip '*/exemaker.exe'
rm exemaker.zip
mv exemaker.exe hg.exe
# zip it and ship it ... or continue running the test suite
cd ..
zip -r hg-winhack-x.x.zip hg-winhack/

Note that this will leave you with both a hg.exe which can be used from windows and a hg.py which might be picked up if you have python with a .py installed.

/i\ This version of exemaker will interpret the relative python path as relative to the current working directory. A new version from timeless should fix that.

4.3. Run the test suite

cd hg-winhack/tests
export TMPDIR=c:/tmp   # to avoid path that contains ~ which in general would require escaping
PATH="`pwd`/../hg-python27:$PATH" ./run-tests.py --local

4.4. Alternative: Building the C extensions with Microsoft Compiler

Get and install the gratis "Microsoft Windows SDK for Windows 7 and .NET Framework 3.5 SP1" from microsoft.com. It contains both the x86 and x64 Microsoft C/C++ compiler.

Building Mercurial's C extensions (*.pyd files in the mercurial folder) for x64 can be done with (assuming an x64 Python 2.6 was installed in C:\Python26_x64):

C:\Python26_x64\python.exe setup.py build_ext -i

(using an x86 python.exe will build the C extensions for x86).

This allows to run the testsuite with an x64 Python with (in the "tests" directory):

python run-tests.py --local

4.5. Run tests involving Git

If you have Git installed on your Windows box, hg-winhack will incorrectly detect that git command is available, and will try to run Git-related tests. It will fail to do so, because it cannot run "git.cmd" from shell.

• If you don't want to run Git tests, edit hghave file to return False instead of return matchoutput('git --version 2>&1', r'^git version')

• If you prefer Git tests to be executed, find your Git installation folder, enter cmd folder and create git file (no extension) with the following contents:

#!/bin/sh $COMSPEC //C git.cmd $* 

5. See also

• ContributingChanges

CategoryDeveloper