{"record":{"id":"47f02233e1f98b61","repo":"hashicorp/packer","slug":"failed-to-generate-a-fingerprint-s","errorCode":null,"errorMessage":"Failed to generate a fingerprint: %s","messagePattern":"Failed to generate a fingerprint: (.+?)","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"internal/hcp/registry/types.version.go","lineNumber":61,"sourceCode":"}\n\n// Initialize prepares the version to be used with HCP Packer.\nfunc (version *Version) Initialize() error {\n\tif version == nil {\n\t\treturn errors.New(\"Unexpected call to initialize for a nil Version\")\n\t}\n\n\t// Bydefault we try to load a Fingerprint from the environment variable.\n\t// If no variable is defined we generate a new fingerprint.\n\tversion.Fingerprint = os.Getenv(env.HCPPackerBuildFingerprint)\n\n\tif version.Fingerprint != \"\" {\n\t\treturn nil\n\t}\n\n\tfp, err := ulid.New(ulid.Now(), ulid.Monotonic(rand.New(rand.NewSource(time.Now().UnixNano())), 0))\n\tif err != nil {\n\t\treturn fmt.Errorf(\"Failed to generate a fingerprint: %s\", err)\n\t}\n\tversion.Fingerprint = fp.String()\n\n\treturn nil\n}\n\n// StoreBuild stores a build for buildName to an active version.\nfunc (version *Version) StoreBuild(buildName string, build *Build) {\n\tversion.builds.Store(buildName, build)\n}\n\n// Build gets the store build associated with buildName in the active version.\nfunc (version *Version) Build(buildName string) (*Build, error) {\n\tbuild, ok := version.builds.Load(buildName)\n\tif !ok {\n\t\treturn nil, errors.New(\"no associated build found for the name \" + buildName)\n\t}\n","sourceCodeStart":43,"sourceCodeEnd":79,"githubUrl":"https://github.com/hashicorp/packer/blob/eb36e3c3e48a036f3e8cc94087636ee72e1303c9/internal/hcp/registry/types.version.go#L43-L79","documentation":"Returned by Version.Initialize when generating a new ULID fingerprint for a version fails. The fingerprint uniquely identifies a version's content in HCP Packer; without it, a new version cannot be initialized.","triggerScenarios":"version.Fingerprint is empty and ulid.New(ulid.Now(), ulid.Monotonic(rand.New(rand.NewSource(time.Now().UnixNano())), 0)) returns an error — essentially only on ULID entropy/monotonic-reader failure.","commonSituations":"Extremely rare; effectively only seen if the system clock/entropy environment is broken. In practice this branch is nearly unreachable on healthy systems.","solutions":["Re-run Packer; the failure is tied to random source state at init time","Check system entropy source (/dev/urandom) and clock sanity if it reproduces","Report a bug if reproducible — the ulid monotonic reader should never fail here under normal conditions"],"exampleFix":null,"handlingStrategy":"retry","validationCode":null,"typeGuard":null,"tryCatchPattern":"if err := version.Initialize(); err != nil && strings.Contains(err.Error(), \"Failed to generate a fingerprint\") {\n    // rare ULID failure: simply retry initialization\n    err = version.Initialize()\n}","preventionTips":["Ensure the machine's entropy source and clock are healthy","Retry initialization on this error — it is not deterministic"],"tags":["ulid","fingerprint","hcp-packer"],"backgroundTag":"fingerprint-generation-failed","analyzedSha":"eb36e3c3e48a036f3e8cc94087636ee72e1303c9","analyzedAt":"2026-09-05T13:20:43.127Z","contentChangedAt":"2026-09-05T13:20:43.127Z","schemaVersion":2},"datasetVersion":"2026-09-12T17:17:11.597Z"}