{"record":{"id":"5cd4c9ea877516a5","repo":"lionsoul2014/ip2region","slug":"failed-to-open-embedded-file-s-w","errorCode":null,"errorMessage":"failed to open embedded file `%s`: %w","messagePattern":"failed to open embedded file `(.+?)`: %w","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"binding/golang/xdb/util.go","lineNumber":300,"sourceCode":"\thandle, err := os.OpenFile(dbFile, os.O_RDONLY, 0600)\n\tif err != nil {\n\t\treturn nil, fmt.Errorf(\"open xdb file `%s`: %w\", dbFile, err)\n\t}\n\tdefer handle.Close()\n\n\tcBuff, err := LoadContent(handle)\n\tif err != nil {\n\t\treturn nil, err\n\t}\n\n\treturn cBuff, nil\n}\n\n// LoadContentFromFS load the whole xdb binary from embed.FS\nfunc LoadContentFromFS(fs embed.FS, filePath string) ([]byte, error) {\n\tfile, err := fs.Open(filePath)\n\tif err != nil {\n\t\treturn nil, fmt.Errorf(\"failed to open embedded file `%s`: %w\", filePath, err)\n\t}\n\tdefer file.Close()\n\n\tvar cBuff []byte\n\tcBuff, err = io.ReadAll(file)\n\tif err != nil {\n\t\treturn nil, fmt.Errorf(\"failed to read embedded file `%s`: %w\", filePath, err)\n\t}\n\n\treturn cBuff, nil\n}\n","sourceCodeStart":282,"sourceCodeEnd":312,"githubUrl":"https://github.com/lionsoul2014/ip2region/blob/c1a1fc7d5941760db3f8431dc05c48cf7f0e30a1/binding/golang/xdb/util.go#L282-L312","documentation":"LoadContentFromFS opens a file inside an embed.FS by path. If fs.Open fails — the path was not embedded, the embed pattern excluded it, or the path is wrong — the error is wrapped as 'failed to open embedded file `%s`: %w'. This is the embedded-asset equivalent of a file-not-found error.","triggerScenarios":"Calling LoadContentFromFS with a filePath that does not match the //go:embed pattern, using an absolute path (embed paths are slash-separated and relative to the package), or the embed directive missing the xdb entirely so compilation embeds nothing.","commonSituations":"Placing the xdb outside the embedded directory; forgetting to add it to //go:embed; using OS-style backslashes on Windows source code; renaming the data directory without updating the embed pattern; build tags excluding the asset.","solutions":["Confirm the //go:embed directive covers the file (e.g. //go:embed data/ip2region.xdb) and the file is committed in that directory.","Use the exact slash-separated package-relative path (e.g. \"data/ip2region.xdb\"), never an absolute path.","Check that embed.FS was non-nil and the file was included via fs.ReadFile or embed.FS listing before searching.","For dynamic assets, fall back to LoadContentFromFile since embed.FS is fixed at compile time."],"exampleFix":"// before\n//go:embed data/*.bin\nvar xdbFS embed.FS\n\ncBuff, err := xdb.LoadContentFromFS(xdbFS, \"data/ip2region.xdb\") // .xdb not matched\n// after\n//go:embed data/ip2region.xdb\nvar xdbFS embed.FS\n\ncBuff, err := xdb.LoadContentFromFS(xdbFS, \"data/ip2region.xdb\")","handlingStrategy":"validation","validationCode":"//go:embed data/ip2region.xdb\nvar xdbFS embed.FS\n\n// at startup:\nif _, err := xdbFS.Open(\"data/ip2region.xdb\"); err != nil {\n    return fmt.Errorf(\"xdb not embedded: %w\", err)\n}","typeGuard":"func embeddedXdbExists(fsys embed.FS, path string) bool {\n    _, err := fs.Stat(fsys, path)\n    return err == nil\n}","tryCatchPattern":"cBuff, err := xdb.LoadContentFromFS(xdbFS, \"data/ip2region.xdb\")\nif err != nil {\n    if errors.Is(err, fs.ErrNotExist) {\n        return fmt.Errorf(\"embed pattern does not include %s\", \"data/ip2region.xdb\")\n    }\n    return err\n}","preventionTips":["Keep the //go:embed pattern in sync with the actual asset path","Use slash-separated package-relative paths, never absolute ones","List embedded files with fs.Glob during tests to confirm inclusion","Remember embed.FS is fixed at compile time; use file-based loading for dynamic data"],"tags":["golang","embed","file-not-found","fs","xdb"],"backgroundTag":"embedded-file-not-found","analyzedSha":"c1a1fc7d5941760db3f8431dc05c48cf7f0e30a1","analyzedAt":"2026-09-02T16:58:39.988Z","contentChangedAt":null,"schemaVersion":2},"datasetVersion":"2026-09-09T21:17:11.164Z"}