FuelLabs/fuels-rs · error

Failed to deploy the contract

Error message

Failed to deploy the contract

What it means

After loading, the setup_program_test! generated code calls loaded_contract.deploy_if_not_exists(&wallet, TxPolicies::default()).await and expects success. The panic means submission or execution of the deploy transaction failed on the local node.

Source

Thrown at packages/fuels-macros/src/setup_program_test/code_gen.rs:162

            quote! {
                let salt: [u8; 32] = #salt;

                let #contract_instance_name = {
                    let load_config = ::fuels::programs::contract::LoadConfiguration::default().with_salt(salt);

                    let loaded_contract = ::fuels::programs::contract::Contract::load_from(
                        #bin_path,
                        load_config
                    )
                    .expect("Failed to load the contract");

                    let response = loaded_contract.deploy_if_not_exists(
                        &#wallet_name,
                        ::fuels::types::transaction::TxPolicies::default()
                    )
                    .await
                    .expect("Failed to deploy the contract");

                    #contract_struct_name::new(response.contract_id, #wallet_name.clone())
                };
            }
        })
        .reduce(|mut all_code, code| {
            all_code.extend(code);
            all_code
        })
        .unwrap_or_default()
}

fn script_loading_code(
    commands: &[LoadScriptCommand],
    project_lookup: &HashMap<String, Project>,
) -> TokenStream {
    commands
        .iter()

View on GitHub (pinned to d9a250a518)

Solutions

1. Re-run the test to rule out a startup race, and check the node logs printed by the test helper
2. Verify fuels and fuel-core versions are paired (SDK version table)
3. Ensure wallets are funded (default setup funds them; custom configs may break this)
4. Switch to manual setup with proper error propagation to see the underlying error

Example fix

// before: macro-generated code
// .await.expect("Failed to deploy the contract") — hides the real error

// after: manual deploy with the error surfaced
let response = loaded_contract
    .deploy_if_not_exists(&wallet, fuels::types::transaction::TxPolicies::default())
    .await?; // Returns the actual failure reason

// Health-check the node before deploying
if provider.node_info().await.is_err() {
    anyhow::bail!("local provider not ready — check node logs before deploying");
}

// Retry with backoff to absorb local-node startup races
let mut attempt = 0;
let response = loop {
    match loaded.deploy_if_not_exists(&wallet, TxPolicies::default()).await {
        Ok(r) => break r,
        Err(e) if attempt < 3 => {
            attempt += 1;
            tokio::time::sleep(std::time::Duration::from_millis(500)).await;
        }
        Err(e) => return Err(e.into()),
    }
};

When it happens

Trigger: The local provider is not yet ready or crashed; the wallet lacks base assets to pay gas; the fuels crate and fuel-core node versions are mismatched so the deploy tx is rejected; transient startup flakiness of the local node.

Common situations: Race between provider startup and the first deploy; version skew after upgrading only one of fuels/fuel-core; resource-starved CI runners.

Related errors

• Error while trying to fetch wallets from the custom provider
• Failed to load the contract
• HOME env var missing
• Failed to download wasm executor: {}

AI-assisted analysis of FuelLabs/fuels-rs@d9a250a518 (2026-08-16). Data as JSON: /api/errors/c74baaa30e53a1e5. Report an issue: GitHub.