{"record":{"id":"bf0649619f51fb55","repo":"pola-rs/polars","slug":"arrow-datatype-dt-not-supported-by-polars-you","errorCode":null,"errorMessage":"Arrow datatype {dt:?} not supported by Polars. You probably need to activate that data-type feature.","messagePattern":"Arrow datatype (.+?) not supported by Polars\\. You probably need to activate that data-type feature\\.","errorType":"panic","errorClass":null,"httpStatus":null,"severity":"error","filePath":"crates/polars-core/src/datatypes/field.rs","lineNumber":315,"sourceCode":"            ArrowDataType::LargeBinary | ArrowDataType::Binary => DataType::Binary,\n            ArrowDataType::FixedSizeBinary(_) => DataType::Binary,\n            ArrowDataType::Map(inner, _keys_sorted) => {\n                let entries = Self::from_arrow_field(inner);\n                #[cfg(feature = \"dtype-map\")]\n                let map = entries.map_from_positional_entries_dtype();\n                #[cfg(not(feature = \"dtype-map\"))]\n                let map: Option<DataType> = None;\n                map.unwrap_or_else(|| DataType::List(entries.boxed()))\n            },\n            ArrowDataType::Interval(IntervalUnit::MonthDayNano) => {\n                check_allow_importing_interval_as_struct(\"month_day_nano_interval\").unwrap();\n                feature_gated!(\"dtype-struct\", DataType::_month_days_ns_struct_type())\n            },\n            ArrowDataType::Interval(IntervalUnit::MonthDayMillis) => {\n                check_allow_importing_interval_as_struct(\"month_day_millisecond_interval\").unwrap();\n                feature_gated!(\"dtype-struct\", DataType::_month_days_ns_struct_type())\n            },\n            dt => panic!(\n                \"Arrow datatype {dt:?} not supported by Polars. \\\n                You probably need to activate that data-type feature.\"\n            ),\n        }\n    }\n}\n\nimpl From<&ArrowField> for Field {\n    fn from(f: &ArrowField) -> Self {\n        Field::new(f.name.clone(), DataType::from_arrow_field(f))\n    }\n}\n","sourceCodeStart":297,"sourceCodeEnd":328,"githubUrl":"https://github.com/pola-rs/polars/blob/68506541d2de983056c9eb244e1ea05fab377dfc/crates/polars-core/src/datatypes/field.rs#L297-L328","documentation":"The catch-all arm of DataType::from_arrow: an Arrow datatype with no polars mapping (typically one gated behind a disabled data-type feature) reaches this panic naming the Arrow dtype. Rebuild polars with the relevant dtype feature or filter the column out before reading.","triggerScenarios":"This panic/expect fires when execution reaches an unguarded state described by: \"Arrow datatype {dt:?} not supported by Polars. You probably need to activate that data-type feature.\". Typical triggers: unsupported dtype or feature-gated code path reached at runtime, invalid user input or environment variable value, calling API methods in the wrong order or on mismatched types, or data (lengths, offsets, ranges) violating the function's preconditions.","commonSituations":"Encountered when input data or configuration does not meet the preconditions of the throwing code path (\"Arrow datatype {dt:?} not supported by Polars. You probably need to activate that data-type feature.\"). Common cases: missing Cargo feature flags, mismatched dtypes/lengths between arrays or series, out-of-range temporal values, malformed environment variables, or operations on unsupported/complex nested types.","solutions":["Activate the cargo feature matching the Arrow data type (e.g. `dtype-array`, `dtype-struct`, `dtype-categorical`, `dtype-decimal`).","Check the polars crate's feature list and enable the `dtype-*` feature for the reported type."],"exampleFix":null,"handlingStrategy":"fallback","validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"68506541d2de983056c9eb244e1ea05fab377dfc","analyzedAt":"2026-08-19T12:15:06.350Z","contentChangedAt":"2026-08-19T12:15:06.350Z","schemaVersion":2},"datasetVersion":"2026-09-14T00:17:10.932Z"}