<div class="hidden-warning"><a href="https://docs.haskellstack.org/"><img src="https://cdn.jsdelivr.net/gh/commercialhaskell/stack/doc/img/hidden-warning.svg"></a></div>

# Setting up

The goal of setting up is a `stack` executable file on the PATH. When Stack is
used, it sets other things up as needed.

*[PATH]: An environment variable that specifies a list of directories searched for executable files.

??? question "How do I know if Stack is on the PATH?"

    Command `stack`. If Stack is available, that should output information about
    how to use it.

??? question "How do I find where Stack is located?"

    === "Unix-like"

        Command `which -a stack`.

    === "Windows"

        Command `where.exe stack`.

??? question "How do I find what version of Stack is available?"

    Command `stack --version` or `stack --numeric-version`.

??? question "If I don't use GHCup, is there a preferred location for Stack?"

    You can put the `stack` executable file anywhere on your PATH. However, a
    good location is the directory where Stack itself will install executables.
    That location depends on the operating system:

    === "Unix-like"

        Stack installs executables to:

        ~~~text
        $HOME/.local/bin
        ~~~

        If you don't have that directory in your PATH, you may need to update
        your PATH. That can be done by editing the `~/.bashrc` file.

    === "Windows"

        Stack installs executables to:

        ~~~text
        %APPDATA%\local\bin
        ~~~

        For example: `C:\Users\<user-name>\AppData\Roaming\local\bin`.

        If you don't have that directory in your PATH, you may need to update
        your PATH. That can be done by searching for 'Edit Environment variables
        for your account' under Start.

    !!! note

        If you used GHCup to install Stack, GHCup puts executable files in the
        `bin` directory in the GHCup root directory.

To get and use Stack, some other things need to be in place first:

<div class="grid cards" markdown>

-   :material-laptop:{ .lg .middle } __A computer__

    ---

    Stack will need at least about 5 GB of disk space[^1]. It will help to know
    what platform your computer provides.

    [^1]:
        About 3 GB for a single version of GHC and about 2 GB for a local copy
        of the Hackage package index.

    *[platform]: Machine architecture (eg x86_64, AArch64) and operating system (eg Linux distribution, macOS, Windows).

-   :material-wifi:{ .lg .middle } __Access to the Internet__

    ---

    Stack will need to fetch files from remote locations.

-   :octicons-terminal-24:{ .lg .middle } __Terminal software__

    ---

    Stack is used at the command line. Your operating system likely provides
    terminal software and alternatives may be available.

-   :material-text-box-edit-outline:{ .lg .middle } __A code editor__

    ---

    You can use any editor program that can edit text files but code editors
    with extensions for Haskell code files are recommended.

</div>

## Install Stack

Stack can be installed on most Linux distributions, macOS and Windows.

??? question "What about other operating systems?"

    Stack is open to supporting more operating systems. To request support for
    an operating system, please submit an
    [issue](https://github.com/commercialhaskell/stack/issues/new) at Stack's
    GitHub repository.

Stack can be installed directly or by using the GHCup tool.

=== "Directly"

    Stack can be installed on various operating systems.

    ??? question "Where can binary distributions for Stack be found?"

        Stack executables are available on the
        [releases](https://github.com/commercialhaskell/stack/releases) page of
        Stack's GitHub repository.

        URLs with the format
        `https://get.haskellstack.org/stable/<PLATFORM>.<EXTENSION>` point to
        the latest stable release. The manual download links use those URLs.

    ??? question "Does the `sh` installation script have flags and options?"

        The `sh` installation script recognises the following optional flags and
        options: `-q` suppresses output and specifies non-intervention (likely a
        prerequisite for the use of the script in CI environments); `-f` forces
        installation, even if an existing Stack executable is detected; and
        `-d <directory>` specifies a destination directory for the Stack
        executable.

    === "Linux"

        For most Linux distributions, on x86_64 or AArch64 machine
        architectures, the easiest way to install Stack is to command either:

        ~~~text
        curl -sSL https://get.haskellstack.org/ | sh
        ~~~

        or:

        ~~~text
        wget -qO- https://get.haskellstack.org/ | sh
        ~~~

        These commands download a script file and run it using `sh`.

        ??? question "Will the installation script need root access?"

            The script at [get.haskellstack.org](https://get.haskellstack.org/)
            will ask for root access using `sudo`. It needs such access in order
            to use your platform's package manager to install dependencies and
            to install to `/usr/local/bin`. If you prefer more control, follow
            the manual installation instructions for your platform below.

        ??? question "Can I download Stack manually?"

            Yes. Manual download for Linux distributions depends on your machine
            architecture, x86_64 or AArch64/ARM64.

            === "x86_64"

                * Click
                  [:material-cloud-download-outline:](https://get.haskellstack.org/stable/linux-x86_64.tar.gz)
                  to download an archive file with the latest release.

                * Extract the archive and place the `stack` executable file
                  somewhere on your PATH.

                * Ensure you have the required system dependencies installed.
                  These include GCC, GNU Make, xz, perl, libgmp, libffi, and
                  zlib. We also recommend Git and GPG.

                The installation of system dependencies will depend on the
                package manager for your Linux distribution. Notes are provided
                for Arch Linux, CentOS, Debian, Fedora, Gentoo and Ubuntu.

                === "Arch Linux"

                    ~~~text
                    sudo pacman -S make gcc ncurses git gnupg xz zlib gmp libffi zlib
                    ~~~

                === "CentOS"

                    ~~~text
                    sudo yum install perl make automake gcc gmp-devel libffi zlib zlib-devel xz tar git gnupg
                    ~~~

                === "Debian"

                    ~~~text
                    sudo apt-get install g++ gcc libc6-dev libffi-dev libgmp-dev make xz-utils zlib1g-dev git gnupg netbase
                    ~~~

                === "Fedora"

                    ~~~text
                    sudo dnf install perl make automake gcc gmp-devel libffi zlib zlib-devel xz tar git gnupg
                    ~~~

                === "Gentoo"

                    Ensure you have the `ncurses` package with `USE=tinfo`. Without
                    it, Stack will not be able to install GHC.

                === "Ubuntu"

                    ~~~text
                    sudo apt-get install g++ gcc libc6-dev libffi-dev libgmp-dev make xz-utils zlib1g-dev git gnupg netbase
                    ~~~

            === "AArch64"

                * Click
                  [:material-cloud-download-outline:](https://get.haskellstack.org/stable/linux-aarch64.tar.gz)
                  to download an archive file with the latest release.

                * Extract the archive and place the `stack` executable file
                  somewhere on your PATH.

                * Ensure you have the required system dependencies installed.
                  These include GCC, GNU Make, xz, perl, libgmp, libffi, and
                  zlib. We also recommend Git and GPG.

                The installation of system dependencies will depend on the
                package manager for your Linux distribution. Notes are provided
                for Arch Linux, CentOS, Debian, Fedora, Gentoo and Ubuntu.

                === "Arch Linux"

                    ~~~text
                    sudo pacman -S make gcc ncurses git gnupg xz zlib gmp libffi zlib
                    ~~~

                === "CentOS"

                    ~~~text
                    sudo yum install perl make automake gcc gmp-devel libffi zlib zlib-devel xz tar git gnupg
                    ~~~

                === "Debian"

                    ~~~text
                    sudo apt-get install g++ gcc libc6-dev libffi-dev libgmp-dev make xz-utils zlib1g-dev git gnupg netbase
                    ~~~

                === "Fedora"

                    ~~~text
                    sudo dnf install perl make automake gcc gmp-devel libffi zlib zlib-devel xz tar git gnupg
                    ~~~

                === "Gentoo"

                    Ensure you have the `ncurses` package with `USE=tinfo`. Without it,
                    Stack will not be able to install GHC.

                === "Ubuntu"

                    ~~~text
                    sudo apt-get install g++ gcc libc6-dev libffi-dev libgmp-dev make xz-utils zlib1g-dev git gnupg netbase
                    ~~~

        ??? question "Can I use a Linux package to get Stack?"

            Some Linux distributions have official or unofficial packages for
            Stack, including Arch Linux, Debian, Fedora, NixOS, openSUSE/SUSE
            Linux Enterprise, and Ubuntu. However, the Stack version available
            as a Linux package may lag behind Stack's current version and, in
            some cases, the lag may be significant.

            !!! info "Linux packages that lag behind Stack's current version"

                If Stack version available as a Linux package lags behind
                Stack's current version, using `stack upgrade --binary-only` is
                recommended after installing it.

            === "Arch Linux"

                The Arch extra package repository provides an official x86_64
                [package](https://www.archlinux.org/packages/extra/x86_64/stack/).
                You can install it with the command:

                ~~~text
                sudo pacman -S stack
                ~~~

                The Arch User Repository (AUR) also provides:

                *   a [`stack-bin` package](https://aur.archlinux.org/packages/stack-bin);
                    and

                *   a [`stack-static` package](https://aur.archlinux.org/packages/stack-static)

            === "Debian"

                There are Debian
                [packages](https://packages.debian.org/search?keywords=haskell-stack&searchon=names&suite=all&section=all)
                for Buster and up. However, the distribution's Stack version
                lags behind.

            === "Fedora"

                Fedora includes Stack, but its Stack version may lag behind.

            === "NixOS"

                Users who follow the `nixos-unstable` channel or the Nixpkgs
                `master` branch can install the latest Stack release into their
                profile with the command:

                ~~~text
                nix-env -f "<nixpkgs>" -iA stack
                ~~~

                Alternatively, the package can be built from source as follows.

                1.  Clone the git repo, with the command:

                    ~~~text
                    git clone https://github.com/commercialhaskell/stack.git
                    ~~~

                2.  Create a `shell.nix` file with the command:

                    ~~~text
                    cabal2nix --shell ./. --no-check --no-haddock > shell.nix
                    ~~~

                    Note that the tests fail on NixOS, so disable them with
                    `--no-check`. Also, Haddock currently doesn't work for
                    Stack, so `--no-haddock` disables it.

                3.  Install Stack to your user profile with the command:

                    ~~~text
                    nix-env -i -f shell.nix
                    ~~~

                For more information on using Stack together with Nix, please
                see the
                [NixOS manual section on Stack](http://nixos.org/nixpkgs/manual/#how-to-build-a-haskell-project-using-stack).

            === "SUSE"

                There is also an unofficial package for openSUSE or SUSE Linux
                Enterprise. Its Stack version may lag behind. To install it:

                === "openSUSE Tumbleweed"

                    ~~~text
                    sudo zypper in stack
                    ~~~

                === "openSUSE Leap"

                    ~~~text
                    sudo zypper ar http://download.opensuse.org/repositories/devel:/languages:/haskell/openSUSE_Leap_42.1/devel:languages:haskell.repo
                    sudo zypper in stack
                    ~~~

                === "SUSE Linux Enterprise 12"

                    ~~~text
                    sudo zypper ar http://download.opensuse.org/repositories/devel:/languages:/haskell/SLE_12/devel:languages:haskell.repo
                    sudo zypper in stack
                    ~~~

            === "Ubuntu"

                There are Ubuntu
                [packages](http://packages.ubuntu.com/search?keywords=haskell-stack&searchon=names&suite=all&section=all)
                for Ubuntu 20.04 and up.

        ??? question "Can I set up auto-completion of Stack commands?"

            Yes. For further information, see the
            [shell auto-completion](topics/shell_autocompletion.md)
            documentation.

    === "macOS"

        Most users of Stack on macOS will also have up to date tools for
        software development.

        ??? question "What if I am not sure that I have those tools?"

            macOS does not come with all the tools required for software
            development but a collection of useful tools, known as the Xcode
            Command Line Tools, is readily available. A version of that
            collection is provided with each version of Xcode (Apple’s
            integrated development environment) and can also be obtained from
            Apple separately from Xcode. The collection also includes the macOS
            SDK (software development kit). The macOS SDK provides header files
            for macOS APIs.

            If you use a command that refers to a common Xcode Command Line Tool
            and the Xcode Command Line Tools are not installed, macOS may prompt
            you to install the tools.

            macOS also comes with a command line tool, `xcode-select`, that can
            be used to obtain the Xcode Command Line Tools. Command
            `xcode-select --print-path` to print the path to the currently
            selected (active) developer directory. If the directory does not
            exist, or is empty, then the Xcode Command Line Tools are not
            installed.

            If the Xcode Command Line Tools are not installed, command
            `xcode-select --install` to open a user interface dialog to request
            automatic installation of the tools.

            An upgrade of macOS may sometimes require the existing Xcode Command
            Line Tools to be uninstalled and an updated version of the tools to
            be installed. The existing tools can be uninstalled by deleting the
            directory reported by `xcode-select --print-path`.

            If, after the installation of Stack, running `stack setup` fails
            with:
            ~~~text
            configure: error: cannot run C compiled programs.
            ~~~

            that indicates that the Xcode Command Line Tools are not installed.

            If building fails with messages that `*.h` files are not found, that
            may also indicate that Xcode Command Line Tools are not up to date.

            Xcode 10 provided an SDK for macOS 10.14 (Mojave) and
            [changed the location](https://developer.apple.com/documentation/xcode-release-notes/xcode-10-release-notes#Command-Line-Tools)
            of the macOS system headers. As a workaround, an extra package was
            provided by Apple which installed the headers to the base system
            under `/usr/include`.

        ??? question "What versions of the LLVM compiler and toolchain are supported?"

            The documentation for each version of GHC identifies the versions of
            LLVM that are supported. That is summarised in the table below for
            recent versions of GHC:

            |GHC version|LLVM versions|
            |-----------|-------------|
            |9.8.2      |11 to 15     |
            |9.6.6      |11 to 15     |
            |9.4.8      |10 to 14     |
            |9.2.8      |9 to 12      |
            |9.0.2      |9, 10 or 12  |
            |8.10.7     |9 to 12      |
            |8.8.4      |7            |
            |8.6.5      |6            |
            |8.4.4      |5            |

        From late 2020, Apple began a transition from Mac computers with Intel
        processors (Intel-based Mac) to
        [Mac computers with Apple silicon](https://support.apple.com/en-gb/HT211814).

        === "Intel-based"

            Intel-based Mac computers have processors with x86_64 architectures.
            For most Intel-based Mac computers, the easiest way to install Stack
            is to command either:

            ~~~text
            curl -sSL https://get.haskellstack.org/ | sh
            ~~~

            or:

            ~~~text
            wget -qO- https://get.haskellstack.org/ | sh
            ~~~

            These commands download a script file and run it using `sh`.

            ??? question "Will the installation script need root access?"

                The script at
                [get.haskellstack.org](https://get.haskellstack.org/)
                will ask for root access using `sudo`. It needs such access in
                order to use your platform's package manager to install
                dependencies and to install to `/usr/local/bin`. If you prefer
                more control, follow the manual installation instructions below.

            ??? question "Can I download Stack manually?"

                Yes:

                * Click
                  [:material-cloud-download-outline:](https://get.haskellstack.org/stable/osx-x86_64.tar.gz)
                  to download an archive file with the latest release for x86_64
                  architectures.

                * Extract the archive and place `stack` somewhere on your PATH.

                Now you can run Stack from the command line in a terminal.

        === "Apple silicon"

            Mac computers with Apple silicon have an M series chip. These chips
            use an architecture known as ARM64 or AArch64.

            For Mac computers with Apple silicon, the easiest way to install
            Stack is to command either:

            ~~~text
            curl -sSL https://get.haskellstack.org/ | sh
            ~~~

            or:

            ~~~text
            wget -qO- https://get.haskellstack.org/ | sh
            ~~~

            These commands download a script file and run it using `sh`.

            ??? question "Will the installation script need root access?"

                The script at
                [get.haskellstack.org](https://get.haskellstack.org/)
                will ask for root access using `sudo`. It needs such access in
                order to use your platform's package manager to install
                dependencies and to install to `/usr/local/bin`. If you prefer
                more control, follow the manual installation instructions below.

            ??? question "What if I get error `C compiler cannot build executables`?"

                The installation of Stack or some packages (e.g. `network`)
                requiring C source compilation might fail with:

                ~~~text
                configure: error: C compiler cannot build executables
                ~~~

                In that case you should pass `-arch arm64` as part of the
                `CFLAGS` environment variable. This setting will be picked up by
                the C compiler of your choice.

                ~~~bash
                # Assuming BASH below

                # passing CFLAGS in-line with the command giving rise to the error
                CFLAGS="-arch arm64 ${CFLAGS:-}" some_command_to_install_stack
                CFLAGS="-arch arm64 ${CFLAGS:-}" stack [build|install]

                # -- OR --

                # ~/.bash_profile
                # NOTE: only do this if you do not have to cross-compile, or remember to unset
                # CFLAGS when needed
                export CFLAGS="-arch arm64 ${CFLAGS:-}"
                ~~~

                The setting instructs the C compiler to compile objects for
                ARM64. These can then be linked with libraries built for ARM64.
                Without the instruction, the C compiler, invoked by Cabal
                running in x86-64, would compile x86-64 objects and attempt to
                link them with existing ARM64 libraries, resulting in the error
                above.

            ??? question "Can I download Stack manually?"

                Yes:

                * Click
                  [:material-cloud-download-outline:](https://get.haskellstack.org/stable/osx-aarch64.tar.gz)
                  to download an archive file with the latest release for
                  AArch64 architectures.

                * Extract the archive and place `stack` somewhere on your PATH.

                Now you can run Stack from the command line in a terminal.

        ??? question "Can I use the Homebrew package manager to get Stack?"

            [Homebrew](https://brew.sh/) is a popular package manager for macOS.
            If you have its `brew` tool installed, you can just command:

            ~~~text
            brew install haskell-stack
            ~~~

            * The Homebrew formula and bottles are **unofficial** and lag
              slightly behind new Stack releases, but tend to be updated within
              a day or two.

            * Normally, Homebrew will install from a pre-built binary (aka "pour
              from a bottle"), but if it starts trying to build everything from
              source (which will take hours), see
              [their FAQ on the topic](https://github.com/Homebrew/brew/blob/master/docs/FAQ.md#why-do-you-compile-everything).

        ??? question "Can I set up auto-completion of Stack commands?"

            Yes. For further information, see the
            [shell auto-completion](topics/shell_autocompletion.md)
            documentation.

    === "Windows"

        Most computers using Windows have a x86_64 machine architecture. More
        recently, Microsoft has provided Windows on Arm that runs on other
        processors.

        === "x86_64"

            On 64-bit Windows, the easiest way to install Stack is to download
            and use the
            [Windows installer](https://get.haskellstack.org/stable/windows-x86_64-installer.exe).

            !!! info "Stack root"

                By default, the Windows installer will set the
                [Stack root](topics/stack_root.md) by setting the `STACK_ROOT`
                environment variable to `C:\sr`.

            !!! note "Anti-virus software"

                Systems with antivirus software may need to add Stack to the
                list of 'trusted' applications.

                You may see a "Windows Defender SmartScreen prevented an
                unrecognized app from starting" warning when you try to run the
                installer. If so, click on **More info**, and then click on the
                **Run anyway** button that appears.

            !!! warning "Long user PATH environment variable"

                The Windows installer for Stack 2.9.1, 2.9.3 and 2.11.1 (only)
                will replace the user `PATH` environment variable (rather than
                append to it) if a 1024 character limit is exceeded. If the
                content of your existing user `PATH` is long, preserve it before
                running the installer.

            We recommend installing to the default location with the installer,
            as that will make `stack install` and `stack upgrade` work correctly
            out of the box.

            ??? question "Can I download Stack manually?"

                Yes:

                * Click
                  [:material-cloud-download-outline:](https://get.haskellstack.org/stable/windows-x86_64.zip)
                  to download an archive file with the latest release.

                * Unpack the archive and place `stack.exe` somewhere on your
                  PATH.

                Now you can run Stack from the command line in a terminal.

        === "Windows on Arm"

            The GHC project does not yet provide a version of GHC that runs on
            Windows on Arm.

    ??? note "China-based users: download"

        As of 24 February 2020, the download link has limited connectivity from
        within mainland China. If you experience this, please proceed by
        manually downloading (ideally via a VPN) and installing Stack following
        the instructions on this page that apply to your operating system.

=== "GHCup"

    The separate [GHCup](https://www.haskell.org/ghcup/) project provides a tool
    that can be used to install Stack and other Haskell-related tools, including
    GHC and
    [Haskell Language Server](https://github.com/haskell/haskell-language-server)
    (HLS). HLS is a program that is used by Haskell extensions for popular code
    editors.

    GHCup provides Stack for some combinations of machine architecture and
    operating system not provided elsewhere.

    By default, the script to install GHCup (which can be run more than once)
    also configures Stack so that if Stack needs a version of GHC, GHCup takes
    over obtaining and installing that version.

??? note "China-based users: configuration"

    After installation, Stack will need to be configured before it can download
    large files consistently from within China (without reliance on a VPN).
    Please add the following to the bottom of the
    [global configuration file](configure/yaml/index.md) (`config.yaml`):

    ~~~yaml
    ###ADD THIS IF YOU LIVE IN CHINA
    setup-info-locations:
    - "http://mirrors.tuna.tsinghua.edu.cn/stackage/stack-setup.yaml"
    urls:
      latest-snapshot: http://mirrors.tuna.tsinghua.edu.cn/stackage/snapshots.json

    package-index:
    - download-prefix: http://mirrors.tuna.tsinghua.edu.cn/hackage/
    ~~~

??? question "What if I am using an HTTP proxy?"

    To use Stack behind a HTTP proxy with IP address *IP* and port *PORT*, first
    set up an environment variable `http_proxy` and then run the Stack command.
    For example:

    === "Unix-like"

        ~~~text
        export http_proxy=IP:PORT
        stack install
        ~~~

        On most operating systems, it is not mandatory for programs to follow
        the 'system-wide' HTTP proxy. Some programs, such as browsers, do honor
        this 'system-wide' HTTP proxy setting, while other programs, including
        Bash, do not. That means configuring 'http proxy setting' in your System
        Preferences (macOS) would not result in Stack traffic going through the
        proxy.

    === "Windows"

        ~~~text
        $Env:http_proxy=IP:PORT
        stack install
        ~~~

        It is not mandatory for programs to follow the 'system-wide' HTTP proxy.
        Some programs, such as browsers, do honor this 'system-wide' HTTP proxy
        setting, while other programs do not. That means configuring
        'http proxy setting' in your Control Panel would not result in Stack
        traffic going through the proxy.

## Upgrade Stack

The Stack project recommends the use of the latest released version of Stack.

If Stack is already installed, upgrading it depends on whether you are using
Stack or GHCup to manage versions of Stack.

=== "Stack"

    ??? warning "If you use GHCup to manage versions of Stack, use it consistently"

        If you used GHCup to install Stack, you should also use GHCup to upgrade
        Stack.

        GHCup uses an executable named `stack` to manage versions of Stack,
        through a file `stack.shim`. Stack will likely overwrite the executable
        on upgrade.

    There are different approaches to upgrading Stack, which vary as between
    Unix-like operating systems (including macOS) and Windows.

    === "Unix-like"

        There are essentially four different approaches:

        <div class="grid cards" markdown>

        -   __Use the `stack upgrade` command__

            ---

            For further information, see the
            [`stack upgrade`](commands/upgrade_command.md) documentation.

        -   __Manual download__

            ---

            Follow the steps above to download manually the newest executable
            and replace the old executable.

        -   __Use the `sh` installation script__

            ---

            Use the `get.haskellstack.org` script with its `-f` flag to
            overwrite the current Stack executable. For example, command
            either:

            ~~~text
            curl -sSL https://get.haskellstack.org/ | sh -s - -f
            ~~~

            or:

            ~~~text
            wget -qO- https://get.haskellstack.org/ | sh -s - -f
            ~~~

        -   __Use a package manager__

            ---

            Follow your normal package manager approach to upgrading. For
            example:

            ~~~text
            apt-get update
            apt-get upgrade
            ~~~

            Be aware that officially released binaries from the distribution may
            lag behind the latest version of Stack significantly.

        </div>

    === "Windows"

        There are essentially two different approaches:

        <div class="grid cards" markdown>

        -   __Use the `stack upgrade` command__

            ---

            For further information, see the
            [`stack upgrade`](commands/upgrade_command.md) documentation.

        -   __Manual download__

            ---

            Follow the steps above to download manually the newest executable
            and replace the old executable.

        </div>

=== "GHCup"

    The separate [GHCup](https://www.haskell.org/ghcup/) project provides
    guidance about how to use GHCup to manage versions of tools such as Stack.
