'MSYS2' / 'Mingw' Notes

The MSYS2 / Mingw project is now hosted at

https://www.msys2.org/wiki/MSYS2-installation/

An installer for a package that only runs on 64 bit Windows but can also build binaries for 32 bit Windows can be downloaded at

https://repo.msys2.org/distrib/x86_64/

Download file msys2-x86_64-20221216.exe or newer.

Development of an MSYS2/Mingw package that runs on 32 bit Windows has been discontinued, but earlier packages are still available at

https://repo.msys2.org/distrib/i686/

Download file msys2-i686-20200517.exe, which is the latest version.

Open a console window, change to the download directory, and run the downloaded .exe file to install the base packet. The installer adds some new entries to the Windows start menu, and you have to click on one of those to open a command line window with the preferred build environment settings. See next chapter.

Klick on the menu entry for the preferred build environment to open an associated console Window.

The default environment for fresh installations seems to be MSYS2 UCRT64 now, but MSYS2 MINGW32 and MSYS2 MINGW64 have been successfully used in the past to build native applications that run on 32 bit and 64 bit Windows versions.

A description of the different build environments can be found here:

MSYS2 Environments
https://www.msys2.org/docs/environments/

The MSYS2 system uses the pacman program to maintain installed packages.

In current installations, it should be sufficient to run

pacman -Syuu

within any of the MSYS2 shells (maybe multiple times after each other) to upgrade all components to the latest versions.

Note for Windows 7: in an installation on Windows 7 32 bit the command updated some basic programs, then asked to close the msys shell and re-open it before continuing by repeating the command. However, it was impossible to re-open a new shell until the machine had been rebooted. So the older way described below for older versions may be generally preferred.

In older installations, updates may need to be run in 2 steps:

First update programs that may be in use:

pacman --needed -S bash pacman pacman-mirrors msys2-runtime

If any packages have been updated, you have to close and re-run the MSYS2 shell before continuing.

Then run

pacman -Syu

to update the remaining packages.

Toolchain to build 32 bit Windows binaries:

pacman -S --needed base-devel mingw-w64-i686-toolchain

Toolchain to build 64 bit Windows binaries (can be used on 64 bit Windows only):

pacman -S --needed base-devel mingw-w64-x86_64-toolchain

meld, the excellent graphical diff and merge tool:

pacman -S --needed mingw-w64-i686-meld3    # The 32 bit version.
pacman -S --needed mingw-w64-x86_64-meld3  # The 64 bit version.

git & gitk:

pacman -S --needed git

This package may be required only if the graphical toool gitk fails to start:

pacman -S --needed mingw-w64-i686-tk    # The 32 bit version.
pacman -S --needed mingw-w64-x86_64-tk  # The 64 bit version.

If you want to use git to not only clone remote repos, you may want to do some basic git configuration that greatly simplifies working with git.

Git for Windows is a different package based on MSYS2/Mingw, but uses a different configuration for the shell and for git.

To avoid problems when working with a Mingw32 or Mingw64 shell in a directory containing a git repo cloned (or maintained) by Git for Windows, some configuration files should be copied from the Git for Windows installation directory (e.g. /c/opt/git/) to the Msys installation directory (e.g. /c/opt/msys32/), namely:

/etc/gitconfig
/etc/gitattibutes
/etc/profile.d/git-prompt.sh

Among other things, this avoids that different line endings are assumed by the different git installations in Git for Windows and Msys2/Mingw.

If an error occurs because a PGP key is missing or has expired, the hints in this paragraph may help to fix the problem.

Note: In the examples below, a WKD key server is explicitly specified because older installations may use the obsolete pool.

If a PGP key is missing or has expired, run the following command to refresh all keys:

pacman-key --keyserver hkp://keyserver.ubuntu.com:80 --refresh-keys

It's possible that the command above has to be run several times to fetch all required keys.

If a key is still missing or can't be updated automatically, import the key manually:

pacman-key --keyserver hkp://keyserver.ubuntu.com:80 -r 5F944B027F7FE2091985AA2EFA11531AA0AA7F57

Then edit the key to increase the trust level. Run

pacman-key --edit-key 5F944B027F7FE2091985AA2EFA11531AA0AA7F57

then enter trust, select level 4 (full), and enter save to save the changes.

Note: in an installation on Windows 7 32 bit level 4 was not saved. The increased trust level was only saved when level '5' (ultimate) was selected. Car must also be taken that the appropriate key for 'y' is pressed (in German, 'j') to accept the level.

Then repeat the command from the basic installation