clockworklabs/SpacetimeDB · error · anyhow::Error

Template definition missing

Error message

Template definition missing

What it means

init_builtin scaffolds a project from an embedded built-in template and requires config.template_def (the parsed TemplateDefinition fetched from the template registry). TemplateConfig construction normally sets template_def: Some(...) only for built-in templates (init.rs:379, 923) and None for GitHub/custom paths — so TemplateType::Builtin reaching init_builtin with template_def None violates the constructor's invariant and this guard fires.

Solutions

1. Retry `spacetime init` (transient registry fetch/parse issues resolve on a clean fetch)
2. Update the CLI so embedded template handling matches the current registry schema
3. Work around by cloning a template from GitHub instead: `spacetime init --template <owner>/<repo>`

Example fix

# before
spacetime init --template <builtin-id>   # hits 'Template definition missing'
# after
spacetime init --template clockworklabs/quickstart-csharp   # GitHub path skips init_builtin

for i in 1 2; do spacetime init "$@" && exit 0; done
spacetime init --template clockworklabs/quickstart-csharp   # GitHub fallback

When it happens

Trigger: A code path that classifies a template as Builtin but fails to attach its definition — e.g. a template id resolved against the fetched registry on one code path but classified Builtin on another, or a registry entry whose definition failed to parse while the id still matched. Not triggerable by ordinary flag combinations in healthy builds.

Common situations: Version skew between the CLI's embedded template handling and the remote template registry format; partially failed template-list fetches where ids survive but definitions don't; custom/enterprise template registries returning unexpected shapes.

Related errors

• No templates found for selected language
• Project initialization did not create spacetimedb directory
• Unknown client language
• Unknown server language
• Aborted.

AI-assisted analysis of clockworklabs/SpacetimeDB@fdd647dfac (2026-08-20). Data as JSON: /api/errors/70279a831a69bf12. Report an issue: GitHub.

Appendix: source

Thrown at crates/cli/src/subcommands/init.rs:1382

    // Install AI assistant rules for multiple editors/tools
    install_ai_rules(config, project_path)?;

    println!("{}", "Project initialized successfully!".green());

    Ok(())
}

fn init_builtin(
    config: &TemplateConfig,
    project_path: &Path,
    is_server_only: bool,
    dotnet_major: Option<u8>,
) -> anyhow::Result<()> {
    let template_def = config
        .template_def
        .as_ref()
        .ok_or_else(|| anyhow::anyhow!("Template definition missing"))?;

    let template_files = embedded::get_template_files();

    if !is_server_only {
        println!(
            "Setting up client ({})...",
            config.client_lang.map(|l| l.as_str()).unwrap_or("none")
        );
        let client_source = &template_def.client_source;
        if let Some(files) = template_files.get(client_source.as_str()) {
            copy_embedded_files(files, project_path)?;
        } else {
            anyhow::bail!("Client template not found: {}", client_source);
        }

        // Update client name
        match config.client_lang {
            Some(ClientLanguage::TypeScript) => {

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