Alien::MSYS - Tools required for GNU style configure scripts on Windows


version 0.17


from Perl:

 use Alien::MSYS;
 # runs uname from MSYS
 my $uname = msys { `uname` };

From Prompt/Makefile

 C:\> perl -MAlien::MSYS -e Alien::MSYS::msys_run uname


MSYS provides minimal shell and POSIX tools on Windows to enable GNU style configure scripts to run (the type usually generated by autoconf). This module aims to provide an interface for using MSYS on Windows and act as a no-op on Unix like operating systems which already have that capability. If you use this module, I recommend that you list this as a prerequisite only during MSWin32 installs.

When installing, this distribution will look for an existing MSYS using the following methods in this order:


If set to share a system install will not be attempted. If set to system then a share install will not be attempted.

environment variable PERL_ALIEN_MSYS_BIN

If set, this environment variable should be set to the root of MSYS (NOT MinGW). For example, if you have MinGW / MSYS installed on D: you might use this:

 C:\> set PERL_ALIEN_MSYS_BIN=D:\MinGW\msys\1.0\bin

Keep in mind that this environment variable is consulted during both install and at run-time, so it is advisable to set this in the System Properties control panel.

search PATH for mingw-get.exe

Second, Alien::MSYS searches the PATH environment variable for the mingw-get.exe program, which is a common method for installing MinGW and MSYS. From there if it can deduce the location of MSYS it will use that.

try C:\MinGW\msys\1.0\bin

Next, Alien::MSYS tries the default install location.

Use desktop shortcut for MinGW Installer

Finally, Alien::MSYS will try to find MSYS from the desktop shortcut created by the GUI installer for MinGW. This method only works if you already have Win32::Shortcut installed, as it is an optional dependency.

If MSYS cannot be found using any of these methods, then it will download and install MSYS in this distribution's share directory.



 # get the uname from MSYS
 my $uname = msys { `uname` };
 # run with GNU make from MSYS instead of
 # dmake from Strawberry Perl
 msys { system 'make' };

This function takes a single argument, a code reference, and runs it with the correctly set environment so that calls to the system function or the qx quote like operator will use MSYS instead of the default environment.


 # pass command through @ARGV
 C:\> perl -MAlien::MSYS -e Alien::MSYS::msys_run uname
 # pass command through @_
 C:\> perl -MAlien::MSYS -e "Alien::MSYS::msys_run 'make'; Alien::MSYS::msys_run 'make install'"

This function runs a command with the MSYS environment. It gets the command and arguments either as passed to it, or if none are passed the the command is expected to be in @ARGV.

If the command fails then it will exit with a non-zero error code. This is useful, in the second example above if either make or make install fails, then the whole command will fail, also make install will not be attempted unless make succeeds.


This function returns the full path to the MSYS bin directory.


This Alien is big and slow to install. I am aware this is an annoying problem. It is also the only reliable way (that I know of) to install packages from source that use autotools on Strawberry or Visual C++ Perl. Here are some things that you can do to avoid this painful cost:

Use the system library if possible

The Alien::Build system is usually smart enough to find the system library if it is available. Alien::MSYS is usually only necessary for so called share installs.

Pre-install MSYS

As mentioned above if you preinstall MSYS and set the PERL_ALIEN_MSYS_BIN environment variable, then you will save yourself some time if you use multiple installs of Perl like I do.

Use another build system

Some projects will provide a makefile that will work with GNU Make and cmd.exe that you can build without MSYS. An example of an Alien that takes advantage of this is Alien::libuv.

Some projects provide both autoconf and CMake. Although using CMake reliably requires Alien::cmake3 for share installs, it is much much lighter than Alien::MSYS.

Also obviously you can open a ticket, or make a pull request with the project that you are alienizing to support build systems that don't suck as much as autoconf.


Strawberry Perl is convenient for building XS modules without any dependencies or just dependencies on the small number of libraries that come bundled with Strawberry Perl. It is very very painful in my opinion if you depend on libraries that are not bundled, which is why this Alien exists. There is an alternative though.

MSYS2 / MinGW provides a MSWin32 Perl as part of a Linux / open source like package that provides probably all of the libraries that you might want to use as dependencies, and if it doesn't you can build much easier than with Strawberry + Alien::MSYS.

There are some notes here:

On using the MSYS2 / MinGW / MSWin32 Perl from the MSYS2 project.


Author: Graham Ollis <>


Shawn Laffan (SLAFFAN, shawnlaffan)


Zaki Mughal (zmughal)


This software is copyright (c) 2013-2022 by Graham Ollis.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.