{"record":{"id":"6e112d165f5b7888","repo":"ReFirmLabs/binwalk","slug":"worker-thread-for-target-file-failed-to-send-res","errorCode":null,"errorMessage":"Worker thread for {target_file} failed to send results back to main thread: {e}","messagePattern":"Worker thread for (.+?) failed to send results back to main thread: (.+?)","errorType":"panic","errorClass":null,"httpStatus":null,"severity":"error","filePath":"src/main.rs","lineNumber":309,"sourceCode":"            Err(_) => {\n                error!(\"Failed to read {target_file} data\");\n                b\"\".to_vec()\n            }\n            Ok(data) => data,\n        };\n\n        // Analyze target file, with extraction, if specified\n        let results = bw.analyze_buf(&file_data, &target_file, do_extraction);\n\n        // If data carving was requested as part of extraction, carve analysis results to disk\n        if do_carve {\n            let carve_count = carve_file_map(&file_data, &results);\n            info!(\"Carved {carve_count} data blocks to disk from {target_file}\");\n        }\n\n        // Report file results back to main thread\n        if let Err(e) = worker_tx.send(results) {\n            panic!(\n                \"Worker thread for {target_file} failed to send results back to main thread: {e}\"\n            );\n        }\n    });\n}\n\n/// Carve signatures identified during analysis to separate files on disk.\n/// Returns the number of carved files created.\n/// Note that unknown blocks of file data are also carved to disk, so the number of files\n/// created may be larger than the number of results defined in results.file_map.\nfn carve_file_map(file_data: &[u8], results: &binwalk::AnalysisResults) -> usize {\n    let mut carve_count: usize = 0;\n    let mut last_known_offset: usize = 0;\n    let mut unknown_bytes: Vec<(usize, usize)> = Vec::new();\n\n    // No results, don't do anything\n    if !results.file_map.is_empty() {\n        // Loop through all identified signatures in the file","sourceCodeStart":291,"sourceCodeEnd":327,"githubUrl":"https://github.com/ReFirmLabs/binwalk/blob/26713972e3f9f52dc37d4a421c4554b0bd9e82ef/src/main.rs#L291-L327","documentation":"Panics inside spawn_worker when a worker thread finishes analyzing a file but the mpsc channel back to the main thread is closed (SendError). It means the main receiver was dropped — the result of the worker's work is lost, so the tool aborts.","triggerScenarios":"The main thread's worker_rx receiver is dropped (main loop exited or panicked) before all workers finish, then a worker calls worker_tx.send(results) which returns Err(e) and hits the panic at src/main.rs:309.","commonSituations":"A panic in the main scheduler loop while workers are still running; process shutdown racing with in-flight workers; refactors that drop the receiver early.","solutions":["Keep the receiver (worker_rx) alive until all workers have completed (join the pool before dropping rx)","Handle the send error gracefully (log and exit) instead of panicking inside the worker thread","Check main-thread logs for an earlier panic that dropped the receiver — fix that root cause","Consider using a scoped thread structure or explicit JoinHandle collection to guarantee rx outlives all senders"],"exampleFix":"// before\nif let Err(e) = worker_tx.send(results) {\n    panic!(\"Worker thread for {target_file} failed to send results back to main thread: {e}\");\n}\n// after\nif let Err(e) = worker_tx.send(results) {\n    eprintln!(\"Failed to send results for {target_file}: {e}\");\n    return;\n}","handlingStrategy":"try-catch","validationCode":"// ensure receiver lives as long as senders\nlet (worker_tx, worker_rx) = mpsc::channel();\n// keep worker_rx alive until workers.active_count() == 0 before dropping","typeGuard":null,"tryCatchPattern":"if let Err(e) = worker_tx.send(results) {\n    eprintln!(\"send failed: {e}\");\n    return; // or set an atomic shutdown flag\n}","preventionTips":["Guarantee the channel receiver outlives all worker threads (join/await pool shutdown before dropping rx)","Fix root-cause panics in the main loop that drop the receiver early","Log send errors instead of panicking inside worker threads","Test worker shutdown ordering under load"],"tags":["rust","panic","channels","concurrency"],"backgroundTag":"broken-pipe","analyzedSha":"26713972e3f9f52dc37d4a421c4554b0bd9e82ef","analyzedAt":"2026-09-06T21:38:04.941Z","contentChangedAt":"2026-09-06T21:38:04.941Z","schemaVersion":2},"datasetVersion":"2026-09-14T00:17:10.932Z"}