Swift

mise can be used to manage multiple versions of swift on the same system. Swift is supported on macOS and Linux.

Usage

Install Swift for the current project and check the selected toolchain:

mise use swift@latest
mise exec -- swift --version

Use mise use -g swift@latest for a personal default. In an existing Swift package with Package.swift, run mise exec -- swift build to build it.

On Linux, Swift archives target specific distributions and require compatible system libraries. mise records the selected distribution in lockfile options; use a lock entry built for your target distribution. The Swift core plugin does not currently support Windows.

When no build matches your distribution

swift.org publishes one build per distribution family. On a host without a published build, mise warns and falls back to another family's build. That build may link against library names your distribution spells differently — an Arch-family host builds ncurses wide-only, so it has libncursesw.so.6 where the fallback build asks for libncurses.so.6 — and the install then fails when mise runs swift --version to check it. mise names the libraries it could not resolve:

this swift build needs shared libraries missing from this host:
libform.so.6, libncurses.so.6, libpanel.so.6

Where the names differ but the libraries are compatible, point the install at a directory of aliases with install_env:

mkdir -p ~/.local/lib/curses-compat
ln -sf /usr/lib/libncursesw.so.6 ~/.local/lib/curses-compat/libncurses.so.6
ln -sf /usr/lib/libformw.so.6 ~/.local/lib/curses-compat/libform.so.6
ln -sf /usr/lib/libpanelw.so.6 ~/.local/lib/curses-compat/libpanel.so.6

[tools]
swift = { version = "6.3.3", install_env = { LD_LIBRARY_PATH = "{{env.HOME}}/.local/lib/curses-compat" } }

The same LD_LIBRARY_PATH belongs in [env] so the toolchain also works after it is installed. Substituting a library is a judgement about compatibility that mise cannot make for you; a distribution that genuinely lacks the library needs that library installed instead.

See a mise guide for Swift developers for how to use mise with swift.

Tool Options

The following tool-options are available for the swift backend. These options go in the [tools] section of mise.toml.

install_env

Set environment variables for install-time commands run by the core swift backend:

[tools]
swift = { version = "latest", install_env = { HTTPS_PROXY = "http://proxy.example" } }

Settings

swift.gpg_verify

• Type: boolean(optional)
• Env: MISE_SWIFT_GPG_VERIFY
• Default: None

Verify OpenPGP signatures for swift (built-in, no external gpg required). Set to false to disable.

swift.platform

• Type: string
• Env: MISE_SWIFT_PLATFORM
• Default: "osx" | "windows10" | "ubuntu24.04" | "debian12" | "fedora41" | "amazonlinux2023" | "ubi9"

Override the distro build to use for precompiled binaries. By default the distro is detected and matched against what the Swift release actually publishes, which changes from release to release. Set this to force a specific build, or to install without reaching swift.org's release index.