Set up Cygwin

This GitHub action sets up Cygwin in your workflow run.

1. Installs Cygwin.
2. Installs any additional packages specified.

Use it in your workflow like this:

- name: Set up Cygwin
  uses: egor-tensin/setup-cygwin@v4
  with:
    packages: cmake gcc-g++

# Cygwin executables are added to PATH, so you can call them directly:
- run: |
    ls.exe -Al
    pwd.exe

# Alternatively, you can set Cygwin's bash as the shell to use:
- run: |
    # This is a real bash script!
    basic() {
        ls -Al
        pwd
    }
    basic
  shell: C:\tools\cygwin\bin\bash.exe --login --norc -eo pipefail -o igncr '{0}'

• Specify any additional packages to be installed as a space-separated list in the packages parameter.
• Set the installation directory using the install-dir parameter (C:\tools\cygwin is the default).
• The CYGWIN environment variable is set to an empty string by default. Provide a custom value using the env parameter.

API

Input	Value	Default	Description
install-dir	empty	✓	Install to C:\tools\cygwin.
	any		Install to the specified directory.
packages	empty	✓	Don't install any additional packages.
	any		Space-separated package names.
env	empty	✓	Set %CYGWIN% to an empty string.
	any		Set %CYGWIN% to the specified value.
hardlinks	any	✓	Don't convert any symlinks.
	1		Convert symlinks in /usr/bin to hardlinks.

The paths to the Cygwin binaries are added to the PATH variable.

Line terminators

When using Cygwin's bash as the shell to run the step script (or if you see something like \r': command not found in logs), make sure that igncr is present in the SHELLOPTS variable be either:

• passing -o igncr to bash.exe,

  job:
    name: Test job
    runs-on: windows-latest
    defaults:
      run:
        shell: C:\tools\cygwin\bin\bash.exe --login -o igncr '{0}'
    steps:
      - ...
  

• or setting the SHELLOPTS variable in the env: block.

  job:
    name: Test job
    runs-on: windows-latest
    env:
      SHELLOPTS: igncr
    defaults:
      run:
        shell: C:\tools\cygwin\bin\bash.exe --login '{0}'
    steps:
      - ...
  

Please avoid using \r\n as line separators in your shell scripts, as Linux shells will choke on them.

Executable symlinks

Some packages install symlinks in /usr/bin along with real executables. An example is package "gcc-core", which (as of November 2021) installs symlink cc, pointing to the real executable gcc.exe. Calling Cygwin symlinks from Windows' command prompt is unsupported, but might be convenient so there's an option to convert them to hardlinks instead (the hardlinks parameter).

License

Distributed under the MIT License. See LICENSE.txt for details.