ErrLookup › PyO3/pyo3

PyO3/pyo3

Rust bindings for the Python interpreter · Rust · 349 source files

Analyzed at ac9b6899d3 on 2026-09-05. 96 documented errors.

Code / Message	Type	Severity	Tags
unexpected error in coroutine waker	panic	error	rust, async, coroutine, waker
overflow adding PY_VECTORCALL_ARGUMENTS_OFFSET	panic	error	rust, pyo3, overflow, ffi
Attaching a thread to the interpreter is prohibited while a…	panic	error	pyo3, gil, gc-traverse, panic
ignored leap-second, `datetime` does not support…	console	warning	rust, pyo3, chrono, datetime, precision-loss
frozenset iteration should be infallible	panic	error	pyo3, iterator, panic, frozenset
should always have positional defaults <= positional…	panic	error	pyo3, proc-macro, signature, internal-invariant
Cannot clone pointer into Python heap without the thread…	panic	critical	gil, thread-attach, py-pointer, panic
Neither abi3 or abi3t features are enabled	validation	error	rust, pyo3, cargo-features, abi3, build-time
failed to create Python string	panic	warning	rust, pyo3, type-error, string-conversion
frozenset should always be iterable	panic	info	rust, pyo3, frozenset, iterator, invariant
failed to import `datetime` C API	panic	critical	rust, pyo3, datetime, c-api, frozen-binary
seconds overflow	panic	info	pyo3, datetime, timedelta, duration, unreachable
this object is already borrowed	panic	error	rust, pyo3, inheritance, borrow-checker
Named fields should have identifiers	panic	error	pyo3, proc-macro, panic, internal-invariant
Empty enum	panic	error	rust, pyo3, derive, enum
The 'weakref' weak reference instance should be valid…	panic	error
Already mutably borrowed	panic	error	rust, pyo3, borrow-checker, reentrancy
Cannot drop pointer into Python heap without the thread…	panic	critical	pyo3, refcount, gil, process-abort
{}	panic	error	pyo3, panic, python-c-api, error-printing
Unknown return value from PyDict_SetDefaultRef	panic	error	pyo3, dict, c-api, panic, python-3-13
Python stdout len didn't return expected number of lines	console	error
Already borrowed	panic	error	rust, pyo3, borrow-checker, pyrefmut
PyErr state should never be invalid outside of normalization	panic	critical	rust, pyo3, pyerr, internal-invariant
0 < N <= 12	panic	error	pyo3, panic, tuple, array
set should always be iterable	panic	error	pyo3, panic, set, iterator
useless `set` - the struct is already annotated with…	validation	error	rust, pyo3-macros, pyclass, duplicate-attribute
size_t should fit the flag bits	panic	error	rust, pyo3-ffi, const-panic, platform
expected error	panic	error	pyo3, panic, string, formatting
out of range integral type conversion attempted on…	panic	error	pyo3, panic, overflow, list
no interpreter executable	panic	error
Cannot get `__mro__` from object.	panic	error	rust, pyo3, pypy, limited-api, types
set iteration should be infallible	panic	error	pyo3, panic, set, iterator
The 'weakref.ProxyType' (or `weakref.CallableProxyType`)…	panic	error
complex enum has a non-unit variant	panic	error	pyo3, proc-macro, enum, internal-invariant
no class given for a class method	panic	error	pyo3, proc-macro, classmethod, internal-invariant
broken Python interpreter	console	error	rust, pyo3, python-interpreter, broken-interpreter, windows, build-time
dictionary changed size during iteration	panic	error	pyo3, dict, iteration, mutation, panic
no class given for Fn with a "self" receiver	panic	error	pyo3, proc-macro, method-generation, internal-invariant
dictionary keys changed during iteration	panic	error	pyo3, dict, iteration, mutation, panic
invalid hex encoding	panic	error	build-script, hex-decoding, panic
failed to convert tuple to list	panic	error	pyo3, panic, tuple, list
`PyFrame_GetBuiltins` returns a `dict`	panic	warning	rust, pyo3, frame, builtins, type-mismatch
cannot fail due to mask	panic	error	rust, pyo3-ffi, invariant, vectorcall
failed to parse PyO3 config	panic	error	rust, build-script, pyo3, configuration
cannot set a minimum Python version	validation	error	rust, pyo3, abi3, version-mismatch, cargo-features, build-time
`get` may only be specified once	validation	error	rust, pyo3, macro, compile-time
Cannot target an abi3t version below	validation	error	rust, pyo3, abi3, free-threaded, version-check, build-time
the configured PyPy interpreter version	console	error	rust, pypy, version-compatibility, build
expected a bool (1/true/True or 0/false/False) for…	validation	error
Python script failed	validation	error	rust, pyo3, python-interpreter, script-failure, build-time
length of buffer fits in Py_ssize_t	panic	info	pyo3, integer-conversion, platform, unreachable
Cannot attach to the Python interpreter while it is…	panic	error	pyo3, gil, interpreter-finalization, shutdown, panic
failed to run the Python interpreter at	validation	error	rust, pyo3, python-interpreter, process-spawn, build-time
cannot set a minimum Python version	console	error
build_flags contains Py_GIL_DISABLED but target_abi	validation	error
RustPython only supports targeting abi3t, it does not allow…	console	error
unsupported Python interpreter	validation	error
Cannot get `__bases__` from object.	panic	error	rust, pyo3, pypy, limited-api, types
unexpected Rust target pointer width	validation	error	rust, pyo3, cross-compilation, pointer-width, build-time
Cannot compile extensions for the free-threaded build on…	console	error
Cannot target free-threaded builds for Python versions…	validation	error
PYO3_CONFIG_FILE must be an absolute path	console	error	rust, pyo3, env-var, path, pyo3-config-file, build-time
named field has an identifier	panic	error	pyo3, proc-macro, enum, internal-invariant
Unknown Py_GIL_DISABLED value	panic	error	build-config, python-interpreter, free-threading, panic
unknown interpreter	validation	error
target_triple_from_env() must be called from a build script	panic	error
At least GraalPy version	console	error	rust, pyo3, graalpy, version-check, build-time
string contains nul bytes	panic	error	ffi, cstr, nul-byte, const-panic, compile-time
Unrecognized TARGET environment variable value	panic	error
wildcard argument names are not supported	validation	error	rust, pyo3-macros, proc-macro, function-signature
The 'weakref.ReferenceType' instance should be valid…	panic	error
Attaching a thread to the interpreter is currently…	panic	error	pyo3, gil, reentrancy, panic
wasi strings are UTF8	panic	error	pyo3, wasi, path-conversion, utf8, panic
Python doc may not contain nul byte, found nul at position	validation	error	rust, pyo3, macro, docstring
`pyo3_build_config::get()` requires a direct dependency on…	panic	error	cargo, build-script, missing-dependency, panic
Could not find _sysconfigdata*.py in	validation	error
`name` may only be specified once	validation	error	rust, pyo3, macro, compile-time
PYO3_CROSS_LIB_DIR variable value is not a valid UTF-8…	console	error
Unexpected type in `__mro__` attribute.	panic	error	rust, pyo3, pypy, limited-api, types
failed to create type object for	panic	critical	pyclass, type-object, initialization, panic
Detected multiple possible Python versions. Please set…	validation	error
Unexpected type in `__bases__` attribute.	panic	error	rust, pyo3, pypy, limited-api, types
missing `message` in `warn` attribute	validation	error	rust, pyo3, macro, attributes
PyObject pointer is null	panic	critical	ffi, null-pointer, pyerr, panic
your Rust target architecture	console	error	rust, cross-compilation, pointer-width, build
`set` may only be specified once	validation	error	rust, pyo3, macro, compile-time
the configured Python interpreter version	console	error	rust, python, version-compatibility, build
attempted to fetch exception but none was set	panic	critical	pyerr, ffi, error-indicator, panic
PyO3 does not support the free-threaded build of CPython…	console	error	rust, python, free-threaded, nogil, version-compatibility
Abi3t builds are not supported on CPython targets before…	console	error	rust, abi3, free-threaded, version-compatibility
Converting PyErr arguments failed	panic	error	pyerr, into-pyobject, conversion, panic
Invalid config that sets both target_abi and abi3.	console	error	rust, pyo3, config-file, schema-validation, abi3, build-time
failed to import exception	panic	error	exceptions, import-error, embedded-python, panic
called `append_to_inittab` but a Python interpreter is…	panic	error	pyo3, embedding, inittab, initialization-order
useless `get` - the struct is already annotated with…	validation	error	rust, pyo3-macros, pyclass, duplicate-attribute
the configured GraalPy interpreter version	console	error	rust, graalpy, version-compatibility, build