Error Codes

DUUMBI outputs structured JSONL errors to stdout. Each error includes a code, message, node ID, and contextual details.

Validation errors (E001–E009)

Code	Error	Description	How to fix
E001	Type mismatch	Operand types don’t match (e.g., Add with i64 and f64)	Ensure both operands have the same type. Use explicit conversion if mixing i64/f64.
E002	Unknown Op	Unrecognized @type in the graph	Check spelling of the @type field. See Op Types for valid ops.
E003	Missing field	Required field not present on a node	Add the missing field. E.g., Add requires duumbi:left and duumbi:right.
E004	Orphan reference	@id reference points to a non-existent node	Verify the @id target exists. Check for typos in the reference path.
E005	Duplicate @id	Two nodes share the same @id	Rename one of the duplicate @id values to be unique.
E006	No entry function	No main function found in the program	Add a function with "@id": "fn:main" to your graph.
E007	Cycle	Circular dependency detected in the graph	Remove the circular reference. Functions can call each other, but data flow must be acyclic.
E008	Link failed	Linker (cc) returned an error	Ensure cc (or $CC) is installed. Check runtime function signatures.
E009	Schema invalid	Node doesn’t match core.schema.json	Validate your JSON-LD against the schema. Check @type and required fields.

Example: E001 fix

// ❌ E001: Add with mismatched types
{
  "@type": "duumbi:Add",
  "duumbi:left": { "@type": "duumbi:Const", "value": 3 },
  "duumbi:right": { "@type": "duumbi:ConstF64", "value": 2.5 }
}

// ✅ Fixed: both operands are i64
{
  "@type": "duumbi:Add",
  "duumbi:left": { "@type": "duumbi:Const", "value": 3 },
  "duumbi:right": { "@type": "duumbi:Const", "value": 2 }
}

Dependency errors (E010–E016)

Code	Error	Description	How to fix
E010	Unresolved cross-module ref	Function call targets a missing module	Add the module as a dependency in config.toml or create it locally.
E011	Dependency not found	Module not in workspace, vendor, or cache	Run duumbi deps install to download missing dependencies.
E012	Module conflict	Two modules provide the same function	Rename one function or use scoped imports.
E013	Registry unreachable	Cannot connect to the registry server	Check network connection. Verify registry URL in config.toml.
E014	Auth failed	Invalid or missing authentication token	Run duumbi registry login <name> to refresh credentials.
E015	Integrity mismatch	Downloaded module hash doesn’t match lockfile	Delete .duumbi/cache/ and re-run duumbi deps install. If persists, update lockfile.
E016	Version not found	Requested version doesn’t exist in registry	Run duumbi search <name> to see available versions. Update version constraint.

Ownership errors (E020–E029)

Code	Error	Description	How to fix
E020	Single owner	Value has multiple owners	Use Move to transfer ownership, or Borrow for shared access.
E021	Use after move	Value accessed after ownership transfer	Access the value before the Move, or clone it.
E022	Borrow exclusivity	&mut T while other borrows exist	End all immutable borrows before creating a mutable borrow.
E023	Lifetime exceeded	Reference outlives its borrowed value	Ensure the reference is dropped before the source value.
E024	Drop incomplete	Owned value not dropped before scope exit	Add a Drop op before the function returns.
E025	Double free	Value dropped more than once	Remove the duplicate Drop op.
E026	Dangling reference	Reference to an already-dropped value	Drop references before dropping the source value.
E027	Move while borrowed	Owner moved while borrows are active	Drop all borrows before moving ownership.
E028	Lifetime param missing	Function needs lifetime annotation	Add lifetime parameters to function signature.
E029	Return lifetime mismatch	Returned reference has wrong lifetime	Ensure returned reference’s lifetime matches the function’s declared lifetime.

Example: E021 fix

// ❌ E021: using a value after it was moved
[
  { "@type": "duumbi:Alloc", "@id": "…/0",
    "duumbi:value": { "@type": "duumbi:ConstString", "value": "hello" } },
  { "@type": "duumbi:Move", "@id": "…/1",
    "duumbi:source": { "@id": "…/0" }, "duumbi:target": "new_owner" },
  { "@type": "duumbi:Print", "@id": "…/2",
    "duumbi:value": { "@id": "…/0" } }  // ← E021: "…/0" was moved
]

// ✅ Fixed: use Borrow instead of Move, or access before Move
[
  { "@type": "duumbi:Alloc", "@id": "…/0",
    "duumbi:value": { "@type": "duumbi:ConstString", "value": "hello" } },
  { "@type": "duumbi:Borrow", "@id": "…/1",
    "duumbi:source": { "@id": "…/0" } },
  { "@type": "duumbi:Print", "@id": "…/2",
    "duumbi:value": { "@id": "…/1" } },
  { "@type": "duumbi:Drop", "@id": "…/3",
    "duumbi:value": { "@id": "…/0" } }
]

See the Ownership Model guide for full rules and diagrams.

Error handling errors (E030–E035)

Code	Error	Description	How to fix
E030	Unhandled Result	result<T,E> not matched or unwrapped	Add a Match op with both ok_block and err_block.
E031	Unhandled Option	option<T> not matched or unwrapped	Add a Match op with both some_block and none_block.
E032	Non-exhaustive match	Match doesn’t cover all variants	Add missing match arms (e.g., both Ok and Err for Result).
E033	Type param mismatch	Result/Option type parameters don’t match	Ensure the Match arms handle the correct types.
E034	Unwrap without check	Unwrap without prior IsOk/IsSome	Add a check (ResultIsOk/OptionIsSome) + Branch before unwrapping, or use Match instead.
E035	Wrong payload type	Unwrapped value type doesn’t match expected	Check the type parameter of the Result/Option matches what you’re extracting.

Example: E030 fix

// ❌ E030: Result not handled
{ "@type": "duumbi:ResultOk", "@id": "…/0",
  "duumbi:value": { "@type": "duumbi:Const", "value": 42 } }
// ...no Match or IsOk check on "…/0"

// ✅ Fixed: use Match for exhaustive handling
{ "@type": "duumbi:Match", "@id": "…/1",
  "duumbi:value": { "@id": "…/0" },
  "duumbi:ok_block": "…/ok_arm",
  "duumbi:err_block": "…/err_arm" }

Error output format

All errors are emitted as structured JSONL to stdout:

{
  "level": "error",
  "code": "E001",
  "message": "Type mismatch: Add expects matching operand types",
  "nodeId": "duumbi:main/main/entry/2",
  "file": "graph/main.jsonld",
  "details": { "expected": "i64", "found": "f64", "field": "duumbi:left" }
}

Fields: level (error/warning), code (E001–E035), message (human-readable), nodeId (graph location), file (source file), details (structured context).