{"record":{"id":"8508a220b7250678","repo":"Egonex-AI/Understand-Anything","slug":"file-disappeared-while-preparing-incremental-updat","errorCode":null,"errorMessage":"File disappeared while preparing incremental update: ${filePath}","messagePattern":"File disappeared while preparing incremental update: (.+?)","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"understand-anything-plugin/skills/understand/prepare-incremental.mjs","lineNumber":343,"sourceCode":"\nfunction analyzeInventoryChanges({\n  currentChangedPaths,\n  currentFingerprints,\n  oldFingerprints,\n  oldInventory,\n  deletedFiles,\n}) {\n  const oldInventorySet = new Set(oldInventory);\n  const fileChanges = [];\n  const newFiles = [];\n  const structurallyChangedFiles = [];\n  const cosmeticOnlyFiles = [];\n  const unchangedFiles = [];\n\n  for (const filePath of currentChangedPaths) {\n    const current = currentFingerprints.files[filePath];\n    if (!current) {\n      throw new Error(`File disappeared while preparing incremental update: ${filePath}`);\n    }\n    const previous = oldFingerprints.files[filePath];\n    if (!oldInventorySet.has(filePath)) {\n      newFiles.push(filePath);\n      fileChanges.push({ filePath, changeLevel: 'STRUCTURAL', details: ['new file'] });\n      continue;\n    }\n    if (!previous) {\n      structurallyChangedFiles.push(filePath);\n      fileChanges.push({\n        filePath,\n        changeLevel: 'STRUCTURAL',\n        details: ['no fingerprint baseline — conservative classification'],\n      });\n      continue;\n    }\n    const result = compareFingerprints(previous, current);\n    fileChanges.push(result);","sourceCodeStart":325,"sourceCodeEnd":361,"githubUrl":"https://github.com/Egonex-AI/Understand-Anything/blob/07edf82a04371b6f69779b067bdc8a1a8753a9db/understand-anything-plugin/skills/understand/prepare-incremental.mjs#L325-L361","documentation":"analyzeInventoryChanges compares git-changed paths against the freshly captured fingerprint scan. Every path the diff reports as changed must exist in currentFingerprints; if it is absent the file vanished between the diff and the scan, making the incremental delta unsound, so the tool aborts rather than produce a wrong graph.","triggerScenarios":"A file is listed in currentChangedPaths (from the git diff) but is missing from currentFingerprints.files — typically because the file was deleted or renamed on disk after the diff was captured but before/while fingerprinting, or an exclude pattern mismatch removed it from the scan.","commonSituations":"Concurrent edits by another process/IDE during incremental preparation, running the tool while a build or formatter is actively deleting/moving files, or a race between git diff and the file scan in a large repo.","solutions":["Re-run prepare-incremental.mjs — the race is usually transient","Commit or clean up any in-flight file deletions/moves before running","Ensure no other process (build, formatter, sync tool) mutates the working tree during preparation","If the file was genuinely deleted, use a fresh full analysis instead of incremental"],"exampleFix":"// before\nif (!current) {\n  throw new Error(`File disappeared while preparing incremental update: ${filePath}`);\n}\n// after\nif (!current) {\n  console.warn(`Skipping vanished file: ${filePath}`);\n  continue;\n}","handlingStrategy":"retry","validationCode":"const changedPaths = getChangedPaths(baseCommit);\nconst missing = changedPaths.filter(p => !fs.existsSync(path.join(projectRoot, p)));\nif (missing.length > 0) throw new Error(`Files vanished before incremental prep: ${missing.join(', ')}`);","typeGuard":"function fileInScan(scan, filePath) { return Boolean(scan?.files && Object.prototype.hasOwnProperty.call(scan.files, filePath)); }","tryCatchPattern":"try {\n  await prepareIncremental(args);\n} catch (err) {\n  if (String(err.message).startsWith('File disappeared')) {\n    await new Promise(r => setTimeout(r, 1000));\n    return prepareIncremental(args); // retry once, files may have settled\n  }\n  throw err;\n}","preventionTips":["Do not run builds, formatters, or file syncs concurrently with incremental preparation","Commit or finish file moves/deletes before running the tool","Re-run the command when the error occurs — it is usually a transient race"],"tags":["filesystem","race-condition","git"],"backgroundTag":"file-not-found","analyzedSha":"07edf82a04371b6f69779b067bdc8a1a8753a9db","analyzedAt":"2026-09-07T23:20:10.829Z","contentChangedAt":"2026-09-07T23:20:10.829Z","schemaVersion":2},"datasetVersion":"2026-09-14T00:17:10.932Z"}