This document is intended to help the user install MSYS and start using it.

INSTALLATION

1. Download: MSYS releases
   • Under the “2026-09-27” release, select: msys2-x86_64-20260927.exe
2. Double-click the executable
   1. Click Next
   2. Enter c:\slosh-msys
   3. Enter SLOSH-MSYS
   4. Wait for the installation
   5. Click Finish (Don’t run MSYS2 now)

3. Choose an environment
   For more see: MSYS-environment

   Name	Prefix	Tool chain	Architecture	C-lib	C++-lib
   MSYS	/usr	gcc	x86_64	cygwin	libstdc++
   UCRT64	/ucrt64	gcc	x86_64	ucrt	libstdc++
   CLANG64	/clang64	llvm	x86_64	ucrt	libc++
   CLANGARM64	/clangarm64	llvm	aarch64	ucrt	libc++
   CLANG32	/clang32	llvm	i686	ucrt	libc++
   MINGW64	/mingw64	gcc	x86_64	msvcrt	libstdc++
   MINGW32	/mingw32	gcc	i686	msvcrt	libstdc++

   • This document assumes you picked UCRT64.
   • Note CLANG: llvm lacks features compared to gcc.
   • Note MINGW: msvcrt is stuck in the past (backward compatibility) so is not c99 compatible.
4. Create taskbar icon
   1. Browse for c:\slosh-msys\ucrt64.exe
   2. Double-click
   3. Pin it to the taskbar

PACKAGE MANAGEMENT

MSYS uses ‘pacman’ for its package management. Some key commands are:

• pacman -Sy - Update database of versions.
• pacman -Su - Update installed packages.
• pacman -Ss - Search for packages.
• pacman -Q - List all installed packages.
• pacman -R - Remove a package.

INITIAL UPDATE

After an initial install, you must update the package database, update the base packages, and install extra packages required by the SLOSH model.

1. Update package database:

    pacman -Syu
    # Prompt: Proceed with installation? [Y/n] Y
    # Prompt: To complete ... terminal closed ... Confirm? [Y/n] Y
   

   Restart the terminal.

2. Update the base packages:

    pacman -Su
    # Prompt: Proceed with installation? [Y/n] Y
   

3. Install required packages:

    pacman -S --needed diffutils git make vim man
    # Prompt: Proceed with installation? [Y/n] Y
   

CONFIGURATION FILES

Beyond installing basic packages, updating your configuration files will significantly improve your MSYS experience. The steps below update .vimrc, .bash_profile, .bashrc, and .minttyrc to enhance Vim, Bash, and the terminal.

1. Minimal ~/.vimrc

    vim ~/.vimrc
   

   Enter the following vimrc

2. Minimal ~/.bash_profile and ~/.bashrc

    mv ~/.bash_profile bash_profile-orig
    vim ~/.bash_profile
   

   Enter the following bash_profile

    mv ~/.bashrc bashrc-orig
    vim ~/.bashrc
   

   Enter the following bashrc

3. Minimal ~/.minttyrc

    vim ~/.minttyrc
   

   Enter the following minttyrc

4. Capture the PATH It is useful to know the MS-Windows path to the home directory in case there are multiple versions of MSYS on a system. It can also come in handy for determining how long ago you installed this version of MSYS.

    a=$(cygpath -m ~) ; d=${a:0:1} ; echo "/${d,,}${a:2}" > ~/PATH
   

5. Close and open To have the configuration files go into effect, it is recommended to close your MSYS prompt and re-open it now.