Cannot run on Python 3.14 because cargo is oudated!?

[hmpf]

If you have a version of cargo (rust package manager) locally that some dependency of argus doesn't like, you may get:

Preparing metadata (pyproject.toml) ... error

  error: subprocess-exited-with-error
  
  × Preparing metadata (pyproject.toml) did not run successfully.
  │ exit code: 1
  ╰─> [10 lines of output]
      error: failed to parse lock file at: /tmp/pip-install-4pnjjimz/rpds-py_f9148f64ac0f4f339de1d5fa79acc01c/Cargo.lock
      
      Caused by:
        lock file version `4` was found, but this version of Cargo does not understand this lock file, perhaps Cargo needs to be updated?
      💥 maturin failed
        Caused by: Cargo metadata failed. Does your crate compile with `cargo build`?
        Caused by: `cargo metadata` exited with an error:
      Error running maturin: Command '['maturin', 'pep517', 'write-dist-info', '--metadata-directory', '/tmp/pip-modern-metadata-xhk0hmfh', '--interpreter', '/../Argus/.tox/py314-django52/bin/python']' returned non-zero exit status 1.
      Checking for Rust toolchain....
      Running `maturin pep517 write-dist-info --metadata-directory /tmp/pip-modern-metadata-xhk0hmfh --interpreter /../Argus/.tox/py314-django52/bin/python`
      [end of output]

Removing local cargo you may get:

Failed to build pydantic-core
…
      Checking if cargo is installed
      cargo 1.93.1 (083ac5135 2025-12-15)
      📦 Including license file `LICENSE`
      🍹 Building a mixed python/rust project
      🔗 Found pyo3 bindings
      🐍 Found CPython 3.14 at /../Argus/.tox/py314-django52/bin/python
      📡 Using build options features, bindings from pyproject.toml
…
         Compiling pydantic-core v2.33.2 (/tmp/pip-install-kya4gwz6/pydantic-core_d88eac0a65ef49c39e451285a956b483)
      error: failed to run custom build command for `pyo3-ffi v0.24.1`
      
      Caused by:
        process didn't exit successfully: `/tmp/pip-install-kya4gwz6/pydantic-core_d88eac0a65ef49c39e451285a956b483/target/release/build/pyo3-ffi-5b9f6eb12e1a3d87/build-script-build` (exit status: 1)
        --- stdout
        cargo:rustc-check-cfg=cfg(Py_LIMITED_API)
        cargo:rustc-check-cfg=cfg(Py_GIL_DISABLED)
        cargo:rustc-check-cfg=cfg(PyPy)
        cargo:rustc-check-cfg=cfg(GraalPy)
        cargo:rustc-check-cfg=cfg(py_sys_config, values("Py_DEBUG", "Py_REF_DEBUG", "Py_TRACE_REFS", "COUNT_ALLOCS"))
        cargo:rustc-check-cfg=cfg(pyo3_disable_reference_pool)
        cargo:rustc-check-cfg=cfg(pyo3_leak_on_drop_without_reference_pool)
        cargo:rustc-check-cfg=cfg(Py_3_7)
        cargo:rustc-check-cfg=cfg(Py_3_8)
        cargo:rustc-check-cfg=cfg(Py_3_9)
        cargo:rustc-check-cfg=cfg(Py_3_10)
        cargo:rustc-check-cfg=cfg(Py_3_11)
        cargo:rustc-check-cfg=cfg(Py_3_12)
        cargo:rustc-check-cfg=cfg(Py_3_13)
        cargo:rustc-check-cfg=cfg(Py_3_14)
        cargo:rerun-if-env-changed=PYO3_CROSS
        cargo:rerun-if-env-changed=PYO3_CROSS_LIB_DIR
        cargo:rerun-if-env-changed=PYO3_CROSS_PYTHON_VERSION
        cargo:rerun-if-env-changed=PYO3_CROSS_PYTHON_IMPLEMENTATION
        cargo:rerun-if-env-changed=PYO3_PRINT_CONFIG
        cargo:rerun-if-env-changed=PYO3_USE_ABI3_FORWARD_COMPATIBILITY
      
        --- stderr
        error: the configured Python interpreter version (3.14) is newer than PyO3's maximum supported version (3.13)
        = help: please check if an updated version of PyO3 is available. Current version: 0.24.1
        = help: set PYO3_USE_ABI3_FORWARD_COMPATIBILITY=1 to suppress this check and build anyway using the stable ABI
      warning: build failed, waiting for other jobs to finish...
      💥 maturin failed
        Caused by: Failed to build a native library through cargo
        Caused by: Cargo build finished with "exit status: 101": `env -u CARGO PYO3_BUILD_EXTENSION_MODULE="1" PYO3_ENVIRONMENT_SIGNATURE="cpython-3.14-64bit" PYO3_PYTHON="/../Argus/.tox/py314-django52/bin/python" PYTHON_SYS_EXECUTABLE="/../Argus/.tox/py314-django52/bin/python" "cargo" "rustc" "--profile" "release" "--features" "pyo3/extension-module" "--message-format" "json-render-diagnostics" "--manifest-path" "/tmp/pip-install-kya4gwz6/pydantic-core_d88eac0a65ef49c39e451285a956b483/Cargo.toml" "--lib" "--crate-type" "cdylib"`
      Rust not found, installing into a temporary directory
      Error: command ['maturin', 'pep517', 'build-wheel', '-i', '/../Argus/.tox/py314-django52/bin/python', '--compatibility', 'off'] returned non-zero exit status 1
      [end of output]

It's a known problem:

• Packages that use maturin/PyO3 don't build on Python3.14 unless PYO3_USE_ABI3_FORWARD_COMPATIBILITY is set PyO3/pyo3#5505
• Is python 3.14 not supported yet? pydantic/pydantic#12149