jdx/mise · error

GitHub relay requires a POSIX target: {}

Error message

GitHub relay requires a POSIX target: {}

What it means

The GitHub relay feature of `mise ssh` is implemented only for POSIX (Unix) platforms (src/cli/ssh.rs:170). When relay is requested on a non-Unix target (e.g. Windows), the `#[cfg(not(unix))]` branch bails, including the relay socket path in the message.

Source

Thrown at src/cli/ssh.rs:170

        )?;
        if let Some(socket) = self.relay_session {
            if scope.is_some() {
                bail!("cannot nest relay sessions");
            }
            #[cfg(unix)]
            {
                crate::ui::ctrlc::exit_on_ctrl_c(false);
                let mut command = self.command;
                if let Some(first) = self.destination {
                    command.insert(0, first);
                }
                return crate::system::remote::interruptible(crate::github_relay::unix::session(
                    &socket, command,
                ))
                .await;
            }
            #[cfg(not(unix))]
            bail!("GitHub relay requires a POSIX target: {}", socket.display());
        }
        let destination = self
            .destination
            .ok_or_else(|| eyre::eyre!("an SSH destination is required"))?;
        if let Some(scope) = scope {
            #[cfg(unix)]
            {
                let mut host = crate::system::remote::ad_hoc_host(
                    &destination,
                    std::env::current_dir()?,
                    &[],
                )?;
                host.port = self.port;
                host.identity_file = self.identity_file;
                host.ssh_options = self.ssh_option;
                return crate::system::remote::ssh(&host, scope, &self.command).await;
            }
            #[cfg(not(unix))]

View on GitHub (pinned to afd2eddd3a)

Solutions

1. Run the relay command on Linux or macOS.
2. Remove the relay flags on Windows and use plain SSH without GitHub relay.
3. Wrap relay usage with an OS check in scripts (e.g. only pass relay flags when `uname` is Linux/Darwin).

Example fix

// before (any OS)
mise ssh host --github-relay ...

// after (script guard)
if [ "$(uname -s)" = Linux ] || [ "$(uname -s)" = Darwin ]; then mise ssh host --github-relay ...; else mise ssh host; fi

const relaySupported = process.platform === 'linux' || process.platform === 'darwin';
if (wantRelay && !relaySupported) throw new Error('GitHub relay requires Linux or macOS');

When it happens

Trigger: Running any `mise ssh` command with GitHub relay options (`--relay-session` or relay scope) on a non-Unix build (Windows), where the unix-only relay session module is compiled out.

Common situations: Using mise ssh relay from Windows or Windows-targeted binaries; cross-platform scripts that unconditionally pass relay flags; CI runners on Windows executing the same relay command used on macOS/Linux.

Understand the failure class

Background: "unsupported platform" / "not supported on this platform" errors: what they mean and how to fix them — this error's family across 47 libraries.

Related errors

• GitHub relay requires Linux or macOS
• only available on unix
• cannot nest relay sessions
• brew import is not supported on windows
• OCI system package layers with symlinks require a unix host

AI-assisted analysis of jdx/mise@afd2eddd3a (2026-09-09). Data as JSON: /api/errors/3a2c7022b2f1e0c9. Report an issue: GitHub.