Setup MSYS2

setup-msys2 is a GitHub Action (GHA) to setup an MSYS2 environment (i.e. MSYS, MINGW32, MINGW64, UCRT64, CLANG32, CLANG64 and/or CLANGARM64 shells)

It provides:

Easy installation and updates
Easy package installation including caching for faster re-runs
A shell helper for running your commands or your whole job in an MSYS2 environment

Usage

  - uses: msys2/setup-msys2@v2

Then, for scripts:

  - shell: msys2 {0}
    run: |
      uname -a

It is also possible to execute specific commands from cmd/powershell scripts/snippets. In order to do so, -c is required:

  - shell: powershell
    run: msys2 -c 'uname -a'

  - shell: cmd
    run: msys2 -c 'uname -a'

Default shell

In order to reduce verbosity, it is possible to set msys2 as the default shell. For example:

  defaults:
    run:
      shell: msys2 {0}
  steps:
  - uses: msys2/setup-msys2@v2
    with:
      update: true
      install: >-
        curl
        git
  - uses: actions/checkout@v4

Build matrix

It is common to test some package/tool on multiple environments, which typically requires installing different sets of packages through option install. GitHub Actions' strategy and matrix fields allow to do so, as explained in docs.github.com: Configuring a build matrix and docs.github.com: jobs.<job_id>.strategy.matrix. See, for instance:

  strategy:
    matrix:
      include:
        - { sys: mingw64, env: x86_64 }
        - { sys: mingw32, env: i686 }
        - { sys: ucrt64,  env: ucrt-x86_64 }
        - { sys: clang64, env: clang-x86_64 }
  steps:
    - uses: msys2/setup-msys2@v2
      with:
        msystem: ${{matrix.sys}}
        install: mingw-w64-${{matrix.env}}-openssl

Alternatively, option pacboy allows using a single matrix variable:

  strategy:
    matrix:
      sys:
        - mingw64
        - mingw32
        - ucrt64
        - clang64
  steps:
    - uses: msys2/setup-msys2@v2
      with:
        msystem: ${{matrix.sys}}
        pacboy: openssl:p

Furthermore, .github/workflows/PKGBUILD.yml is a Reusable Workflow to build and test a package in GitHub Actions using a PKGBUILD recipe. It can be used along with matrix (a Composite Action), as shown in .github/workflows/Tool.yml.

Note: By default, GitHub Actions terminates any running jobs if any job in matrix fails. This default behavior can be disabled by setting fail-fast: false in strategy section. See docs.github.com: jobs.<job_id>.strategy.fail-fast for more details.

Find similar patterns in the following workflows:

Find further details at #171 and #102.

Options

msystem

Type: string
Allowed values: MSYS | MINGW64 | MINGW32 | UCRT64 | CLANG32 | CLANG64 | CLANGARM64
Default: MINGW64

The default environment that is used in the msys2 command/shell provided by this action.

MSYS2 recommends UCRT64 nowadays as the default instead of MINGW64.

For example:

  - uses: msys2/setup-msys2@v2
    with:
      msystem: UCRT64

The environment can be later overridden using the MSYSTEM environment variable if needed. This is useful when multiple commands need to be executed in different contexts. For example, in order to build a PKGBUILD file and then test the installed artifact:

  - uses: msys2/setup-msys2@v2
    with:
      msystem: MSYS
  - shell: msys2 {0}
    run: |
      makepkg-mingw -sCLfc --noconfirm --noprogressbar
      pacman --noconfirm -U mingw-w64-*-any.pkg.tar.xz
  - run: |
      set MSYSTEM=UCRT64
      msys2 -c '<command to test the package>'

update

Type: boolean
Default: false

By default, the installation is not updated; hence package versions are those of the installation tarball. By setting option update to true, the action will update the package database and all already installed packages.

  - uses: msys2/setup-msys2@v2
    with:
      update: true

install

Type: string
Allowed values: a whitespace separated list of packages
Default: -

Installing additional packages after updating the system is supported through option install. The package or list of packages are installed through pacman --noconfirm -S --needed --overwrite *.

  - uses: msys2/setup-msys2@v2
    with:
      update: true
      install: >-
        git
        curl

pacboy

Type: string
Allowed values: s whitespace separated list of packages
Default: -

Installing additional packages with pacboy after updating the system is supported through option pacboy. The package or list of packages are installed through pacboy --noconfirm -S --needed.

  strategy:
    fail-fast: false
    matrix:
      sys: [ MINGW64, MINGW32, UCRT64, CLANG64 ]
  steps:
  - uses: msys2/setup-msys2@v2
    with:
      msystem: ${{matrix.sys}}
      install: >-
        git
        curl
      pacboy: >-
        openssl:p

platform-check-severity

Type: string
Allowed values: warn | fatal
Default: fatal

By default (fatal), throw an error if the runner OS is not Windows. If set to warn, simply log a message and skip the rest:

  - uses: msys2/setup-msys2@v2
    with:
      platform-check-severity: warn

Advanced Options

These options are rarely needed and shouldn't be used unless there is a good reason.

path-type

Type: string
Allowed values: minimal | strict | inherit
Default: minimal

Defines which parts of the Windows $env:PATH environment variable leak into the MSYS2 environment. Allowed values:

strict: do not inherit anything from $env:PATH.
minimal (default): only inherit the default Windows paths from $env:PATH (so that cmd.exe and powershell.exe are available for example).
inherit: inherit everything; warning: this can lead to interference with other tools installed on the system.

  - uses: msys2/setup-msys2@v2
    with:
      path-type: minimal

This option corresponds to the MSYS2_PATH_TYPE setting in MSYS2; hence it can be overridden per step through env. See msys2/MSYS2-packages: filesystem/profile for further details about the configuration of each option.

cache

Type: boolean
Default: true

By default (true), caches various things between runs to make repeated runs faster.

  - uses: msys2/setup-msys2@v2
    with:
      cache: false

location

Type: string
Default: -

Specify an alternate location where to install MSYS2 to.

  - uses: msys2/setup-msys2@v2
    with:
      location: D:\

release

Type: boolean
Default: true

If true (the default) it makes a fresh install of the latest MSYS2 installer release. If false it will try to re-use the existing MSYS2 installation which is part of the official GitHub Actions Runner Images.

  - uses: msys2/setup-msys2@v2
    with:
      release: false

Known Problems

actions/checkout and line endings

In case you use the actions/checkout action in your workflow and haven't configured git attributes for line endings, then git might auto convert your text files in the git repo to Windows line endings, which might lead to problems with tools provided by MSYS2.

To work around this issue disable the auto conversion before running actions/checkout:

  steps:
  - run: git config --global core.autocrlf input
  - uses: actions/checkout@v4

msys2 / setup-msys2

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