{"record":{"id":"1232716e8ee7539d","repo":"lionsoul2014/ip2region","slug":"failed-to-read-embedded-file-s-w","errorCode":null,"errorMessage":"failed to read embedded file `%s`: %w","messagePattern":"failed to read embedded file `(.+?)`: %w","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"binding/golang/xdb/util.go","lineNumber":307,"sourceCode":"\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":289,"sourceCodeEnd":312,"githubUrl":"https://github.com/lionsoul2014/ip2region/blob/c1a1fc7d5941760db3f8431dc05c48cf7f0e30a1/binding/golang/xdb/util.go#L289-L312","documentation":"LoadContentFromFS loads an xdb file embedded in the Go binary via go:embed by reading it with io.ReadAll. This error wraps any failure of that read (including the initial os.Open reported through the same wrapping style) so the underlying cause (missing embedded path, permission denied, I/O error) is preserved with %w. It indicates the embedded xdb content could not be materialized into memory.","triggerScenarios":"Calling LoadContentFromFS with a file path that was not embedded via //go:embed, an incorrect relative path (embed paths must not start with / or contain ..), or an I/O/read error while reading the opened embedded file.","commonSituations":"Renaming or moving an .xdb file after the embed directive was written, forgetting the //go:embed annotation so the FS is empty, typo in the path passed to LoadContentFromFS, or running from a context where the embedded FS was populated with a subdirectory prefix.","solutions":["Verify the path passed to LoadContentFromFS exactly matches the //go:embed pattern and its location relative to the Go package directory","Ensure the xdb file exists in the module and is covered by a //go:embed directive in the same package","Print/log the wrapped error's Unwrap() to identify the root cause (e.g. file not found vs permission)","If loading from an external file at runtime instead, use LoadContentFromFile rather than the FS variant"],"exampleFix":"// before\ncontent, err := xdb.LoadContentFromFS(\"ip.v6.xdb\") // file not embedded\n// after\n//go:embed data/ip.v6.xdb\nvar xdbFS embed.FS\ncontent, err := xdb.LoadContentFromFS(\"data/ip.v6.xdb\")","handlingStrategy":"try-catch","validationCode":"// verify embed coverage before calling\npat := filepath.ToSlash(filePath)\nif _, err := embeddedFS.Open(pat); err != nil { return fmt.Errorf(\"not embedded: %w\", err) }","typeGuard":"func isEmbedded(fsys fs.FS, path string) bool { _, err := fs.Stat(fsys, path); return err == nil }","tryCatchPattern":"content, err := xdb.LoadContentFromFS(path)\nif err != nil {\n    var pe *fs.PathError\n    if errors.As(err, &pe) { log.Fatalf(\"embed path %s: %v\", pe.Path, pe.Err) }\n    return err\n}","preventionTips":["Keep //go:embed directives adjacent to the code that loads the FS","Use embed.FS listing (fs.WalkDir) in a unit test to assert the xdb is present","Avoid leading '/' and '..' in embed paths","Add a startup smoke test that loads content once and fails fast"],"tags":["go","embed","file-io","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"}