wavetermdev/waveterm · error

unexpected output from uname: %s

Error message

unexpected output from uname: %s

What it means

After successfully running 'uname -sm', GetClientPlatform parses the output expecting exactly two whitespace-separated fields (OS and architecture). This error is thrown when the lowercased, trimmed output does not split into exactly 2 fields, so the platform cannot be normalized. Unlike the run-failure error, the command succeeded but returned unexpected text.

Source

Thrown at pkg/remote/connutil.go:71

		arch = "arm64"
	}
	return arch
}

// returns (os, arch, error)
// guaranteed to return a supported platform
func GetClientPlatform(ctx context.Context, shell genconn.ShellClient) (string, string, error) {
	blocklogger.Infof(ctx, "[conndebug] running `uname -sm` to detect client platform\n")
	stdout, stderr, err := genconn.RunSimpleCommand(ctx, shell, genconn.CommandSpec{
		Cmd: "uname -sm",
	})
	if err != nil {
		return "", "", fmt.Errorf("error running uname -sm: %w, stderr: %s", err, stderr)
	}
	// Parse and normalize output
	parts := strings.Fields(strings.ToLower(strings.TrimSpace(stdout)))
	if len(parts) != 2 {
		return "", "", fmt.Errorf("unexpected output from uname: %s", stdout)
	}
	os, arch := normalizeOs(parts[0]), normalizeArch(parts[1])
	if err := wavebase.ValidateWshSupportedArch(os, arch); err != nil {
		return "", "", err
	}
	return os, arch, nil
}

func GetClientPlatformFromOsArchStr(ctx context.Context, osArchStr string) (string, string, error) {
	parts := strings.Fields(strings.TrimSpace(osArchStr))
	if len(parts) != 2 {
		return "", "", fmt.Errorf("unexpected output from uname: %s", osArchStr)
	}
	os, arch := normalizeOs(parts[0]), normalizeArch(parts[1])
	if err := wavebase.ValidateWshSupportedArch(os, arch); err != nil {
		return "", "", err
	}
	return os, arch, nil

View on GitHub (pinned to a4447c1563)

Solutions

1. SSH into the remote host and run 'uname -sm' manually; remove any echo/banner output from shell startup files that pollutes stdout.
2. Check that the login shell for the remote user is a standard shell (bash/sh/zsh) without custom wrappers.
3. If uname output is genuinely non-standard, fall back to GetClientPlatformFromOsArchStr with a known os/arch string.
4. Inspect the string embedded in the error to see the actual polluted output and fix accordingly.

Example fix

// before (remote ~/.bashrc)
echo "Welcome to my server"
// after
[ -z "$PS1" ] || echo "Welcome to my server"  # only for interactive shells

if err := shell.Run(ctx, "uname -sm"); err != nil {
    return err
} // and inspect output has exactly 2 fields before calling GetClientPlatform indirectly

os, arch, err := connutil.GetClientPlatform(ctx, shell)
if err != nil && strings.Contains(err.Error(), "unexpected output from uname") {
    os, arch, err = connutil.GetClientPlatformFromOsArchStr(ctx, manualOsArch)
}

When it happens

Trigger: The remote 'uname -sm' output has more or fewer than 2 fields: multi-line output from shell profile banners (motd echoed to stdout), shells wrapping commands, custom PS1/prompt leaking into captured stdout, or a shell printing an error line before uname output.

Common situations: Remote accounts with login banners or 'echo' statements in .bashrc/.profile; restricted shells that print warnings; wrapped/forked shells appending output; non-standard uname implementations printing extra columns.

Related errors

• invalid format of user@host argument
• error running uname -sm: %w, stderr: %s
• invalid ssh remote name (%s): %w
• unexpected version format: %s
• failed to create remote command: %w

AI-assisted analysis of wavetermdev/waveterm@a4447c1563 (2026-09-01). Data as JSON: /api/errors/01e48794411797f1. Report an issue: GitHub.