FuelLabs/fuels-rs · error

abigen generation failed

Error message

abigen generation failed

What it means

abigen! is a proc macro: it parses the macro input, loads the ABI file(s) from disk, and runs bindings generation (Abigen::generate). Any failure anywhere in that pipeline is collapsed into this single .expect at compile time, so the message alone does not say which step failed.

Solutions

1. Run forc build (forc build --release) so the ABI json exists at the path given to abigen!
2. Fix the path: it resolves relative to the crate root, e.g. "tests/contracts/my_contract/out/release/my_contract-abi.json"
3. Validate the file is readable, valid JSON (jq empty or similar)
4. cargo clean and rebuild if stale artifacts are suspected; update fuels to the version matching your forc

Example fix

// before: path does not exist because the contract was never built
abigen!(Contract(name = "MyContract", abi = "out/release/token_ops-abi.json"));

// after: build first, and point at the real artifact
// (shell) forc build --release
abigen!(Contract(name = "MyContract", abi = "tests/contracts/token_ops/out/release/token_ops-abi.json"));

# (shell) make sure the ABI exists and is valid JSON before cargo build
forc build --release
test -f tests/contracts/my_contract/out/release/my_contract-abi.json \
  && jq empty tests/contracts/my_contract/out/release/my_contract-abi.json

When it happens

Trigger: Compiling a crate whose abigen! references an abi path that does not exist relative to the crate root (commonly out/release/*-abi.json missing because forc build was not run), malformed macro syntax, unreadable or invalid JSON, or ABI constructs the generator does not support.

Common situations: Forgetting to run forc build before cargo build/test; moving or renaming contract directories; wrong relative path; forc/fuels version mismatch.

Related errors

• Failed to resolve log type
• Add an `Abigen(..)` command!
• log id should be a valid u64 string
• log id should be a valid u64 string
• Only one `Abigen` command allowed

AI-assisted analysis of FuelLabs/fuels-rs@d9a250a518 (2026-08-16). Data as JSON: /api/errors/2ccc6e8c0031d81b. Report an issue: GitHub.

Appendix: source

Thrown at packages/fuels-macros/src/lib.rs:40

/// `ProgramType` is either `Contract`, `Script` or `Predicate`.
///
/// `ABI_SOURCE` is a string literal representing either a path to the JSON ABI
/// file or the contents of the JSON ABI file itself.
///
///```text
/// abigen!(Contract(
///         name = "MyContract",
///         abi = "packages/fuels/tests/contracts/token_ops/out/release/token_ops-abi.json"
///     ));
///```
///
/// More details can be found in the [`Fuel Rust SDK Book`](https://fuellabs.github.io/fuels-rs/latest)
#[proc_macro]
pub fn abigen(input: TokenStream) -> TokenStream {
    let targets = parse_macro_input!(input as MacroAbigenTargets);

    Abigen::generate(targets.into(), false)
        .expect("abigen generation failed")
        .into()
}

#[proc_macro]
pub fn wasm_abigen(input: TokenStream) -> TokenStream {
    let targets = parse_macro_input!(input as MacroAbigenTargets);

    Abigen::generate(targets.into(), true)
        .expect("abigen generation failed")
        .into()
}

/// Used to reduce boilerplate in integration tests.
///
/// More details can be found in the [`Fuel Rust SDK Book`](https://fuellabs.github.io/fuels-rs/latest)
#[proc_macro]
pub fn setup_program_test(input: TokenStream) -> TokenStream {
    let test_program_commands = parse_macro_input!(input as TestProgramCommands);

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