Building Git

We build Git for Windows using MSys2.

As we are in the process of switching away from msysGit as our development environment, the following instructions are a little rough on the edges. This situation should become better over the next months.

Installing a build environment

1. Install MSys2 from https://msys2.github.io/, into C:/msys32 and C:/msys64 (if you only want to build for one architecture, you can skip the other one). This will install three Shells into the Start Menu: the MSys, the MinGW 32 and the MinGW 64 Shell. To build Git, you should start the MinGW shell corresponding to the architecture of the installed MSys2.

2. Add the Git for Windows-specific Pacman repository: insert the following lines into your /etc/pacman.conf, before the [mingw] line (it is important :

[git-for-windows] Server = https://git-for-windows.github.io/pacman-repository/$arch SigLevel = Optional

3. Update via Pacman: pacman -Syu (as the msys2-runtime gets updated, the MSys Shell needs to be restarted afterwards).

Build Git

1. Install (MSys2) Git: pacman -S git. That Git is based on MSys2, i.e. it is not a MinGW Git. However, we need a working Git to check out the Git source, eh? 😀

2. Clone Git: cd /usr/src/ && git clone https://github.com/git-for-windows/git.

3. Install the Toolchain (gcc etc): pacman -S mingw-w64-<arch>-toolchain, where <arch> is either i686 or x86_64.

4. Install Git's dependencies: pacman -S python less openssh patch make tar diffutils ca-certificates perl-Error perl perl-Authen-SASL perl-libwww perl-MIME-tools perl-Net-SMTP-SSL perl-TermReadKey winpty-git mingw-w64-<arch>-curl mingw-w64-<arch>-expat mingw-w64-<arch>-openssl mingw-w64-<arch>-tcl mingw-w64-<arch>-pcre

5. Temporarily: In /usr/src/git/, check out the update-to-2.3.0 branch: git remote add -f dscho https://github.com/dscho/git && git checkout -t dscho/update-to-2.3.0.

6. Build Git. Some dependencies might be missing, still, e.g. subversion, gettext, man, mingw-w64--gdb, binutils or texinfo (these packages were installed manually before the first successful Git for Windows build).

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Note: if you encounter messages like 39 [main] make 7628 child_info_fork::abort:... while running make, follow the following MSYS2 Issue post, in short: close all MSys2 windows and run the autorebase.bat script in the top-level MSys2 directory from a cmd.

Build the msys2-⁠runtime

1. Install the MSys2 Toolchain: pacman -⁠S gcc binutils make.

2. Clone the MSYS2-packages repository: cd /usr/src && git clone https://github.com/git-for-windows/MSYS2-packages.

3. Temporarily: In MSYS2-packages, check out the msys-runtime branch: git remote add -f dscho https://github.com/dscho/MSYS2-packages && git checkout -t dscho/msys-runtime.

4. Build the package: makepkg -⁠s.

(You might need to call pacman -S ca-certificates to reinstall that package, it seems that it was not installed properly at least in one MSys2 32-bit setup.)