{"record":{"id":"f1a5de619dd6f924","repo":"pola-rs/polars","slug":"invalid-value-for-polars-record-batch-prefetch-siz","errorCode":null,"errorMessage":"invalid value for POLARS_RECORD_BATCH_PREFETCH_SIZE: {x}","messagePattern":"invalid value for POLARS_RECORD_BATCH_PREFETCH_SIZE: (.+?)","errorType":"panic","errorClass":null,"httpStatus":null,"severity":"error","filePath":"crates/polars-stream/src/nodes/io_sources/ipc/builder.rs","lineNumber":57,"sourceCode":"\n#[cfg(feature = \"ipc\")]\nimpl FileReaderBuilder for IpcReaderBuilder {\n    fn reader_name(&self) -> &str {\n        \"ipc\"\n    }\n\n    fn reader_capabilities(&self) -> ReaderCapabilities {\n        use ReaderCapabilities as RC;\n\n        RC::ROW_INDEX | RC::PRE_SLICE\n    }\n\n    fn set_execution_state(&self, execution_state: &crate::execute::StreamingExecutionState) {\n        let prefetch_limit = std::env::var(\"POLARS_RECORD_BATCH_PREFETCH_SIZE\")\n            .map(|x| {\n                x.parse::<NonZeroUsize>()\n                    .unwrap_or_else(|_| {\n                        panic!(\"invalid value for POLARS_RECORD_BATCH_PREFETCH_SIZE: {x}\")\n                    })\n                    .get()\n            })\n            .unwrap_or(\n                // Similar to Parquet.\n                execution_state\n                    .num_pipelines\n                    .saturating_mul(2)\n                    .max(get_request_budget() as usize)\n                    .clamp(16, 2048),\n            )\n            .max(1);\n\n        let prefetch_kbytes_limit = std::env::var(\"POLARS_RECORD_BATCH_PREFETCH_KBYTES_BUDGET\")\n            .map(|x| {\n                x.parse::<NonZeroUsize>()\n                    .unwrap_or_else(|_| {\n                        panic!(\"invalid value for POLARS_RECORD_BATCH_PREFETCH_KBYTES_BUDGET: {x}\")","sourceCodeStart":39,"sourceCodeEnd":75,"githubUrl":"https://github.com/pola-rs/polars/blob/9b5d73fd00236295624374b075d16b1fe6ec6df9/crates/polars-stream/src/nodes/io_sources/ipc/builder.rs#L39-L75","documentation":"Panic in IpcReaderBuilder::set_execution_state: POLARS_RECORD_BATCH_PREFETCH_SIZE was set but is not a valid NonZeroUsize. The env var overrides the default number of prefetched record batches, so the unparsable value {x} aborts reader initialization.","triggerScenarios":"Invalid value in POLARS_RECORD_BATCH_PREFETCH_SIZE.","commonSituations":"See trigger scenarios.","solutions":["Set POLARS_RECORD_BATCH_PREFETCH_SIZE to a positive integer or unset it."],"exampleFix":"export POLARS_RECORD_BATCH_PREFETCH_SIZE=8","handlingStrategy":"validation","validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"9b5d73fd00236295624374b075d16b1fe6ec6df9","analyzedAt":"2026-08-19T12:15:06.350Z","contentChangedAt":"2026-08-19T12:15:06.350Z","schemaVersion":2},"datasetVersion":"2026-09-14T05:17:10.506Z"}