{"record":{"id":"4e9e4b700e30e736","repo":"yorukot/superfile","slug":"error-generating-pdf-thumbnail-outputpath-s","errorCode":null,"errorMessage":"error generating pdf thumbnail, outputPath: %s : %w","messagePattern":"error generating pdf thumbnail, outputPath: (.+?) : %w","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"src/pkg/file_preview/thumbnail_generator.go","lineNumber":96,"sourceCode":"\treturn strings.ToLower(ext) == \".pdf\"\n}\n\nfunc (g *pdfGenerator) generateThumbnail(inputPath string, outputPathWithoutExt string) (string, error) {\n\toutputPath := outputPathWithoutExt + thumbOutputExt\n\tctx, cancel := context.WithTimeout(context.Background(), thumbGenerationTimeout)\n\tdefer cancel()\n\n\t// pdftoppm -singlefile -png prefixFilename\n\tpdftoppm := exec.CommandContext(ctx, \"pdftoppm\",\n\t\t\"-singlefile\",        // output only the first page as image\n\t\t\"-jpeg\",              // Image extension\n\t\tinputPath,            // Set input file\n\t\toutputPathWithoutExt, // The output prefix. (pdftoppm will add the .jpg ext)\n\t)\n\n\terr := pdftoppm.Run()\n\tif err != nil {\n\t\treturn \"\", fmt.Errorf(\"error generating pdf thumbnail, outputPath: %s : %w\",\n\t\t\toutputPath, err)\n\t}\n\n\treturn outputPath, nil\n}\n\ntype psGenerator struct{}\n\nfunc newPsGenerator() (*psGenerator, error) {\n\tif !isGhostscriptInstalled() {\n\t\treturn nil, errors.New(\"ghostscript is not installed\")\n\t}\n\n\treturn &psGenerator{}, nil\n}\n\nfunc (g *psGenerator) supportsExt(ext string) bool {\n\textension := strings.ToLower(ext)","sourceCodeStart":78,"sourceCodeEnd":114,"githubUrl":"https://github.com/yorukot/superfile/blob/b72f550bc6e75913f48eb49fdd258e1a2df2fe88/src/pkg/file_preview/thumbnail_generator.go#L78-L114","documentation":"This error is returned when the pdftoppm child process exits non-zero while rasterizing the first page of a PDF into a JPEG thumbnail. It wraps pdftoppm's stderr, which explains the actual rasterization failure. The output prefix (outputPathWithoutExt) is used because pdftoppm appends the extension itself.","triggerScenarios":"generateThumbnail invoking pdftoppm on a PDF when poppler-utils is not installed, the PDF is encrypted or corrupt, the PDF uses features pdftoppm can't render, or the output directory for outputPathWithoutExt is not writable.","commonSituations":"poppler-utils missing in slim Docker images; password-protected PDFs; damaged downloads; PDFs with zero pages; disk-full or permission-denied on the thumbnail cache directory.","solutions":["Check pdftoppm is installed: `which pdftoppm`; install poppler-utils if absent.","Open the PDF in a viewer / run `pdftoppm <file>` manually to confirm the file is valid.","If the PDF is encrypted, decrypt or skip thumbnailing for encrypted documents.","Verify the output directory exists and is writable.","Fall back to a generic PDF icon when generation fails."],"exampleFix":"// before\nthumb, err := gen.generateThumbnail(pdfPath)\n// after\nthumb, err := gen.generateThumbnail(pdfPath)\nif err != nil {\n    log.Warnf(\"pdf thumbnail failed: %v\", err)\n    thumb = defaultPDFIconPath\n}","handlingStrategy":"try-catch","validationCode":"if _, err := exec.LookPath(\"pdftoppm\"); err != nil { return errors.New(\"poppler-utils not installed\") }\nif fi, err := os.Stat(pdfPath); err != nil || fi.Size() == 0 { return errors.New(\"pdf missing or empty\") }","typeGuard":null,"tryCatchPattern":"thumb, err := gen.generateThumbnail(pdfPath)\nif err != nil {\n    log.Warnf(\"pdf thumbnail failed: %v\", err)\n    thumb = \"\" // fall back to PDF icon\n}","preventionTips":["Ensure poppler-utils is part of deployment images.","Skip encrypted/corrupt PDFs early (e.g. detect via header or pdftotext probe).","Verify the thumbnail output directory is writable before generating.","Cache negative results so a bad PDF isn't reprocessed."],"tags":["pdftoppm","thumbnail","external-command","pdf"],"backgroundTag":"pdftoppm-thumbnail-failed","analyzedSha":"b72f550bc6e75913f48eb49fdd258e1a2df2fe88","analyzedAt":"2026-09-01T04:38:08.254Z","contentChangedAt":null,"schemaVersion":2},"datasetVersion":"2026-09-08T10:18:20.063Z"}