zed-industries/zed · error · anyhow::Error

unsupported os

Error message

unsupported os

What it means

platform::Host::current_platform maps Rust's compile-time env::consts::OS onto the WIT platform::Os enum, which only has Mac, Linux, and Windows. Any other OS string — FreeBSD, OpenBSD, DragonFly, Android, etc. — bails with "unsupported os". Because the value is a build-time constant, the error fires deterministically for every extension that queries the platform on such a build.

Source

Thrown at crates/extension_host/src/wasm_host/wit/since_v0_8_0.rs:868

    async fn github_release_by_tag_name(
        &mut self,
        repo: String,
        tag: String,
    ) -> wasmtime::Result<Result<github::GithubRelease, String>> {
        maybe!(async {
            let release = ::http_client::github::get_release_by_tag_name(
                &repo,
                &tag,
                self.host.http_client.clone(),
            )
            .await?;
            Ok(release.into())
        })
        .await
        .to_wasmtime_result()
    }
}

impl platform::Host for WasmState {
    async fn current_platform(
        &mut self,
    ) -> wasmtime::Result<(platform::Os, platform::Architecture)> {
        Ok((
            match env::consts::OS {
                "macos" => platform::Os::Mac,
                "linux" => platform::Os::Linux,
                "windows" => platform::Os::Windows,
                _ => return Err(wasmtime::Error::msg("unsupported os")),
            },
            match env::consts::ARCH {
                "aarch64" => platform::Architecture::Aarch64,
                "x86_64" => platform::Architecture::X8664,
                _ => return Err(wasmtime::Error::msg("unsupported architecture")),
            },
        ))

View on GitHub (pinned to 5a9b9558db)

Solutions

1. Run on macOS, Linux, or Windows where the host is supported
2. If porting the app, patch the match to add an arm (e.g. map freebsd to platform::Os::Linux only if the WIT enum is also extended — otherwise keep extensions disabled)
3. Report the platform gap upstream so the WIT Os enum grows a variant

// gate extension features before any platform query
if !matches!(std::env::consts::OS, "macos" | "linux" | "windows") {
    // skip current_platform() / disable platform-dependent extension paths
}

fn is_supported_os() -> bool {
    matches!(std::env::consts::OS, "macos" | "linux" | "windows")
}

When it happens

Trigger: Running the extension host binary on an OS other than macOS, Linux, or Windows (e.g. FreeBSD port, Android/Termux) and having any extension call current_platform().

Common situations: Community builds of the editor for BSD variants, or an embedded use of the extension_host crate on a niche platform; every wasm extension that gates download logic on platform fails immediately.

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

• unsupported architecture
• `run_slash_command` not available prior to v0.1.0
• `context_server_command` not available prior to v0.2.0
• `context_server_configuration` not available prior to v0.5.0
• `suggest_docs_packages` not available prior to v0.1.0

AI-assisted analysis of zed-industries/zed@5a9b9558db (2026-08-20). Data as JSON: /api/errors/f333703e3fe95022. Report an issue: GitHub.