{"record":{"id":"b619017efabbd5fc","repo":"Zackriya-Solutions/meetily","slug":"failed-to-open-file-for-append","errorCode":null,"errorMessage":"Failed to open file for append: {}","messagePattern":"Failed to open file for append: (.+?)","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"frontend/src-tauri/src/summary/summary_engine/model_manager.rs","lineNumber":524,"sourceCode":"                log::warn!(\"Server doesn't support resume, starting fresh download\");\n            }\n            (response.content_length().unwrap_or(0), false)\n        } else {\n            let mut active = self.active_downloads.write().await;\n            active.remove(model_name);\n            return Err(anyhow!(\"Download failed with status: {}\", response.status()));\n        };\n\n        log::info!(\"Total size: {} MB\", total_size / (1024 * 1024));\n\n        // Open file for append if resuming, or create new\n        let file = if resuming {\n            OpenOptions::new()\n                .write(true)\n                .append(true)\n                .open(&file_path)\n                .await\n                .map_err(|e| anyhow!(\"Failed to open file for append: {}\", e))?\n        } else {\n            fs::File::create(&file_path)\n                .await\n                .map_err(|e| anyhow!(\"Failed to create file: {}\", e))?\n        };\n\n        // Use 8MB buffer to reduce disk I/O syscalls (major performance improvement)\n        let mut writer = BufWriter::with_capacity(8 * 1024 * 1024, file);\n\n        let mut downloaded: u64 = if resuming { existing_size } else { 0 };\n\n        // Emit initial progress (showing resumed position if applicable)\n        if let Some(ref callback) = progress_callback {\n            callback(DownloadProgress::new(downloaded, total_size, 0.0));\n        }\n        log::info!(\n            \"Starting at {:.1} MB / {:.1} MB\",\n            downloaded as f64 / (1024.0 * 1024.0),","sourceCodeStart":506,"sourceCodeEnd":542,"githubUrl":"https://github.com/Zackriya-Solutions/meetily/blob/0281737d87d26352fb0adc78c8c0975f691b23d1/frontend/src-tauri/src/summary/summary_engine/model_manager.rs#L506-L542","documentation":"On the resume path (server returned 206), OpenOptions with write+append failed on the existing partial file. Something invalidated the file between the size probe and the open: it was deleted, its permissions changed, or another process locked it.","triggerScenarios":"Partial file deleted by a cleaner/sync tool after the Range request succeeded; read-only models directory; Windows file lock from antivirus or a second app instance; models directory on unmounted external storage.","commonSituations":"Two instances of the app downloading the same model; AV scanning the partial .gguf while it is reopened; utilities that remove 'unfinished' downloads.","solutions":["If the partial file is gone or corrupt, delete any remnants and retry without a Range header (fresh download)","Close other app instances that may hold the file, then retry","Fix directory permissions and exclude the models directory from AV/sync tools","Retry after remounting the volume that hosts the models directory"],"exampleFix":null,"handlingStrategy":"fallback","validationCode":"// Verify the partial file is still openable before requesting a resume\nif existing_size > 0 {\n    match tokio::fs::OpenOptions::new().append(true).open(&file_path).await {\n        Ok(_) => { /* safe to resume */ }\n        Err(_) => { tokio::fs::remove_file(&file_path).await.ok(); /* fall back to fresh */ }\n    }\n}","typeGuard":null,"tryCatchPattern":"match download_result {\n    Err(e) if e.to_string().starts_with(\"Failed to open file for append\") => {\n        tokio::fs::remove_file(&file_path).await.ok();\n        manager.download_model_detailed(name, cb).await // fresh download, no Range\n    }\n    other => other,\n}","preventionTips":["Re-check that the partial file still exists and is writable right before the Range request","Prevent multiple app instances from downloading the same model (single-instance lock)","Exclude the models directory from AV/sync tools that lock or delete partial files"],"tags":["filesystem","resume","download","rust"],"backgroundTag":"file-open-permission-denied","analyzedSha":"0281737d87d26352fb0adc78c8c0975f691b23d1","analyzedAt":"2026-08-16T20:57:52.567Z","schemaVersion":2},"datasetVersion":"2026-08-16T23:17:17.608Z"}