How to install gcc and clang on Windows using MSYS

Knowledge Base

Installation of gcc and clang is not very complicated, but there are some issues in corporate environment which I would like to note.

A very first step of course, download in install MSYS2

MSYS2 is a collection of tools and libraries providing you with an easy-to-use environment for building, installing and running native Windows software.

Download MSYS2

Home page: https://www.msys2.org/

Download link: msys2-x86_64-20250221.exe

Installing MSYS2 requires 64 bit Windows 10 or newer.

Install GCC and CLANG

There are only few commands needs to be executed in the terminal

pacman -S mingw-w64-ucrt-x86_64-gcc
pacman -S mingw-w64-ucrt-x86_64-clang

Pacman update

pacman -Sy
pacman -Syu

Add to PATH

This folder C:\msys64\ucrt64\bin needs to be added to Path Environment Variable.

Check

From command prompt execute to get current versions (as per 30-APR-2025):

GCC:

gcc -v
Using built-in specs.
COLLECT_GCC=C:\msys64\ucrt64\bin\gcc.exe
...
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 15.1.0 (Rev1, Built by MSYS2 project)

CLANG:

clang -v
clang version 20.1.3
Target: x86_64-w64-windows-gnu
Thread model: posix
InstalledDir: C:/msys64/ucrt64/bin

Troubleshooting

If you have troubles with SSL, then this check can be disabled in C:\msys64\etc\pacman.conf:

# /etc/pacman.conf
#
# GENERAL OPTIONS
#
[options]
HoldPkg     = pacman
# SSL AND SIGNAURE OFF
XferCommand = /usr/bin/curl -k -L -o %o %u
LocalFileSigLevel = Never
RemoteFileSigLevel = Never
SigLevel = Never
...
Architecture = auto
Color
CheckSpace
ParallelDownloads = 5

Local database located in C:\msys64\var\lib\pacman\sync. Delete, if gets damaged by firewall.

Mirrorlists are located here: C:\msys64\etc\pacman.d\mirrorlist.*

You may need to keep here the servers only where you have access to:

# See https://www.msys2.org/dev/mirrors

## Primary
Server = https://repo.msys2.org/mingw/clang64/