{"record":{"id":"072709ffeb38c44f","repo":"hashicorp/nomad","slug":"error-opening-root-dir-q-w","errorCode":null,"errorMessage":"error opening root dir %q: %w","messagePattern":"error opening root dir %q: %w","errorType":"error_code","errorClass":null,"httpStatus":null,"severity":"error","filePath":"client/lib/fifo/fifo_unix.go","lineNumber":76,"sourceCode":"\t}\n\tdefer root.Close()\n\n\t// also uses O_NOFOLLOW under the hood\n\tf, err := root.OpenFile(base, os.O_WRONLY, 0)\n\tif err != nil {\n\t\treturn nil, fmt.Errorf(\"error opening writer at %s: %w\", path, err)\n\t}\n\treturn f, nil\n}\n\n// Remove a fifo that already exists at a given path\nfunc Remove(path string) error {\n\tdir := filepath.Dir(path)\n\tbase := filepath.Base(path)\n\n\troot, err := os.OpenRoot(dir)\n\tif err != nil {\n\t\treturn fmt.Errorf(\"error opening root dir %q: %w\", dir, err)\n\t}\n\tdefer root.Close()\n\n\treturn root.Remove(base)\n}\n\nfunc IsClosedErr(err error) bool {\n\terr2, ok := err.(*os.PathError)\n\tif ok {\n\t\treturn err2.Err == os.ErrClosed\n\t}\n\treturn false\n}\n","sourceCodeStart":58,"sourceCodeEnd":90,"githubUrl":"https://github.com/hashicorp/nomad/blob/482b49bf1aec006f089bcfc7e632d8f6ac303e5e/client/lib/fifo/fifo_unix.go#L58-L90","documentation":"Remove deletes an existing FIFO at a given path, opening its parent directory with os.OpenRoot first so the unlink happens safely relative to that directory. This error is returned when opening that parent directory fails, typically ENOENT or EACCES, meaning the removal could not even be attempted.","triggerScenarios":"Calling fifo.Remove(path) when filepath.Dir(path) does not exist, the process lacks search/write permission on the directory, or the directory path is wrong/unmounted.","commonSituations":"Idempotent cleanup code calling Remove on cleanup paths whose parent directories were already deleted; wrong configured path; permission changes after container teardown.","solutions":["Treat ENOENT as success in cleanup paths (errors.Is(err, fs.ErrNotExist) → ignore)","Verify the parent directory exists before calling Remove, or skip removal","Check directory permissions for the removing user","Correct the configured FIFO path"],"exampleFix":"// before\nerr := fifo.Remove(\"/run/containerd/io/stdout\")\n// after\nif err := fifo.Remove(\"/run/containerd/io/stdout\"); err != nil && !errors.Is(err, fs.ErrNotExist) {\n\treturn err\n}","handlingStrategy":"try-catch","validationCode":"if fi, err := os.Stat(filepath.Dir(path)); err != nil || !fi.IsDir() {\n\t// skip removal; nothing to clean\n}","typeGuard":null,"tryCatchPattern":"if err := fifo.Remove(path); err != nil && !errors.Is(err, fs.ErrNotExist) {\n\treturn err\n}","preventionTips":["Treat ENOENT during cleanup as success","Verify directory existence before removal in teardown code","Keep cleanup idempotent so repeated teardown is safe","Check permissions when running teardown as a different user"],"tags":["go","filesystem","fifo","cleanup"],"backgroundTag":"fifo-open-failed","analyzedSha":"482b49bf1aec006f089bcfc7e632d8f6ac303e5e","analyzedAt":"2026-09-04T07:54:14.808Z","contentChangedAt":"2026-09-04T07:54:14.808Z","schemaVersion":2},"datasetVersion":"2026-09-08T10:18:20.063Z"}