PyO3/pyo3 · error

Neither abi3 or abi3t features are enabled

Error message

Neither abi3 or abi3t features are enabled

What it means

pyo3's build config requires one of the `abi3` or `abi3t` (free-threaded stable ABI) cargo features to be enabled when a stable-ABI configuration is being derived. `default_stable_abi_config` is only reached when the build expects a stable ABI target, and finding neither feature enabled means the stable ABI request is inconsistent with the declared features, so the build fails immediately with this message.

Source

Thrown at pyo3-build-config/src/impl_.rs:2323

}

/// Generates "default" interpreter configuration when compiling stable ABI extensions
/// without a working Python interpreter.
///
/// `abi3_version` or `abi3t_version` specifies the minimum supported Stable ABI
/// CPython version and which stable ABI to target.
///
/// This should work for most CPython extension modules when compiling on
/// Windows, macOS and Linux.
///
/// Must be called from a PyO3 crate build script.
fn default_stable_abi_config(
    host: &Triple,
    abi3_version: Option<PythonVersion>,
    abi3t_version: Option<PythonVersion>,
) -> Result<InterpreterConfig> {
    if abi3_version.is_none() && abi3t_version.is_none() {
        bail!("Neither abi3 or abi3t features are enabled")
    }
    let (stable_abi, version) = if let Some(version) = abi3_version {
        (StableAbi::Abi3, version)
    } else if let Some(version) = abi3t_version {
        (StableAbi::Abi3t, version)
    } else {
        unreachable!();
    };

    if stable_abi == StableAbi::Abi3t && version < MINIMUM_SUPPORTED_VERSION_ABI3T {
        bail!("Cannot target an abi3t version below {MINIMUM_SUPPORTED_VERSION_ABI3T}")
    }

    // FIXME: PyPy & GraalPy do not support the Stable ABI.
    let target_abi = PythonAbiBuilder::new(PythonImplementation::CPython, version)
        .stable_abi(stable_abi)
        .finalize()?;
    let builder = InterpreterConfigBuilder::new(PythonImplementation::CPython, version)

View on GitHub (pinned to ac9b6899d3)

Solutions

1. Add `abi3` (or `abi3t` for free-threaded Python) to the pyo3 feature list in Cargo.toml
2. If you do not want the stable ABI, remove whatever invokes the abi3 configuration path (e.g. abi3-pyXY features or PYO3 abi3-related env settings)
3. Run `cargo tree -e features` to confirm the abi3 feature actually reaches pyo3, since features are unified across the dependency graph

Example fix

// before
pyo3 = { version = "0.22", features = ["extension-module"] }
// after
pyo3 = { version = "0.22", features = ["extension-module", "abi3-py38"] }

# Cargo.toml check before building
// shell
 cargo tree -e features | grep -q 'pyo3 .*abi3' || echo 'abi3 feature missing: add features = ["abi3"] to pyo3'

When it happens

Trigger: Enabling stable-ABI-related configuration (e.g. PYO3_USE_ABI3_FORWARD_COMPATIBILITY paths, cross-compilation config files, or pyo3-build-config internals that call default_stable_abi_config) without enabling the `abi3` or `abi3t` cargo feature on the pyo3 dependency.

Common situations: Developers toggle `features = ["abi3"]` off while leaving other abi3 settings in place; Cargo feature resolution strips `abi3` because another crate in the graph disabled it; hand-written build scripts or config-generation code call into pyo3-build-config expecting a stable ABI but never declare the feature.

Related errors

• cannot set a minimum Python version {} higher than the inter
• Cannot target an abi3t version below {MINIMUM_SUPPORTED_VERS
• Invalid config that sets both target_abi and abi3.
• failed to run the Python interpreter at {}: {}
• Python script failed

AI-assisted analysis of PyO3/pyo3@ac9b6899d3 (2026-09-05). Data as JSON: /api/errors/43b0750167451373. Report an issue: GitHub.