What causes "Recipe build failed: {}" in aaif-goose/goose?

Retry generation with a more descriptive conversation as the source

Recipe build failed: {}

Error message

Recipe build failed: {}

What it means

Thrown when RecipeBuilder::build() rejects the assembled recipe during LLM recipe generation. build() enforces three invariants (crates/goose/src/recipe/mod.rs:409): a title, a description, and at least one of prompt/instructions. The '{}' is one of those static messages ('Title is required', 'Description is required', or "At least one of 'prompt' or 'instructions' is required").

Source

Thrown at crates/goose/src/agents/agent.rs:3960

            } else {
                (
                    "Custom recipe from chat".to_string(),
                    "a custom recipe instance from this chat session".to_string(),
                )
            };

        let recipe = Recipe::builder()
            .title(title)
            .description(description)
            .instructions(instructions)
            .activities(activities)
            .extensions(extension_configs)
            .settings(settings)
            .author(author)
            .build()
            .map_err(|e| {
                tracing::error!("Failed to build recipe: {}", e);
                anyhow!("Recipe build failed: {}", e)
            })?;

        tracing::info!("Recipe creation completed successfully");
        Ok(recipe)
    }
}

fn recipe_conversation_history(messages: &Conversation) -> Vec<Message> {
    // The recipe prompt has no turn-context instructions; drop the blocks.
    messages
        .agent_visible_messages()
        .into_iter()
        .filter(|message| !message.is_turn_context())
        .collect()
}

#[cfg(test)]
mod tests {

View on GitHub (pinned to 3810898a74)

Solutions

Retry generation with a more descriptive conversation as the source
Use a stronger model that reliably produces title and description
If embedding, supply explicit title/description via the builder instead of relying on extraction
Hand-author the recipe YAML with all required fields

Example fix

// before
Recipe::builder()
    .instructions(instructions)
    .activities(activities)
    .build()?; // Err: Title is required

// after
Recipe::builder()
    .title(title)
    .description(description)
    .instructions(instructions)
    .activities(activities)
    .build()?

Defensive patterns

Strategy: validation

Validate before calling

// Rust — check builder invariants before calling build()
let ok = !title.trim().is_empty()
    && !description.trim().is_empty()
    && (!instructions.trim().is_empty() || !prompt.trim().is_empty());
if !ok { /* regenerate or fill in fields explicitly */ }

Prevention

Always set title, description, and instructions (or prompt) on RecipeBuilder — they are required
Provide explicit title/description when generating from thin conversations
Hand-author YAML for recipes you will reuse instead of regenerating

When it happens

Trigger: Recipe generation completes but the extracted title/description came out empty, or both instructions and prompt are absent (e.g. every parsing path produced nothing usable), so the final builder validation fails.

Common situations: Models returning an empty title/description; upstream parsing fallbacks yielding empty strings; conversations with no derivable subject (tiny or empty transcript).

Related errors

AI-assisted analysis of aaif-goose/goose@3810898a74 (2026-08-16). Data as JSON: /api/errors/a7135f31d3571aa0. Report an issue: GitHub.