Moved derive unit API to DLUnit

Derived units now use a DLUnit class similar to a DLPak to be easily
stored and loaded, the public API has been updated to either take a
DLUnit object or a Path where it reads the DLUnit from a *.dlunit file

The .dlunit file is a ZIP compressed archive containing two files, a
manifest.json which stores the units uuid, its input signals and its
output signal, and unit.py which is the python code for the unit, the
same rules apply (one python function with a specifically structured
signature) as when a string was passed in the old API

Errors have been added to have a DLUnitError similar to the DLPakError
as the DLUnit class is heavily inspired from the DLPak architecutre

Logging may still be primitive, this will be covered in the next AI
logging sweep to homogenize and clean up the logging aspect of things

docs/API.md

@@ -310,14 +310,23 @@ while it is paused, has not started, or has reached the end of the recording.
 ## Derived Signals
 
 A derive unit calculates a new value whenever one of its input signals receives
-an update and all inputs have non-stale live values. Define the calculation as a
-Python source string and bind it with `bind_derive_unit()`.
+an update and all inputs have non-stale live values. Package the calculation,
+its input descriptors, and its output descriptor in a `DLUnit`, then bind it
+with `bind_derive_unit()`.
 
-### `bind_derive_unit(function, input_signals, output_signal) -> UUID`
+### `bind_derive_unit(dlunit: DLUnit | None = None, file: Path | None = None) -> UUID`
+
+Provide exactly one of `dlunit` or `file`:
+
+- `dlunit` binds an in-memory `DLUnit`.
+- `file` loads and binds a `.dlunit` archive.
+
+To create and bind an in-memory unit:
 
 ```python
 from uuid import uuid4
 
+from dynalab_core.dlunit import DLUnit
 from dynalab_core.protocols.packets.handshake import SignalDescriptor
 
 processing_function = """
@@ -332,25 +341,42 @@ def add(left: ValueDescriptor, right: ValueDescriptor, output: SignalDescriptor)
     )
 """
 
-output_signal = SignalDescriptor(
+return_signal = SignalDescriptor(
     id=uuid4(),
     name="Total",
     type="number",
     origin="derived",
 )
 
+derive_unit = DLUnit()
+derive_unit.set_manifest(
+    uuid4(),
+    [left_signal, right_signal],
+    return_signal,
+)
+derive_unit.set_data(processing_function)
+
+unit_id = core.bind_derive_unit(dlunit=derive_unit, file=None)
+```
+
+To bind a previously saved archive instead, pass `None` for `dlunit` and its
+path for `file`:
+
+```python
+from pathlib import Path
+
 unit_id = core.bind_derive_unit(
-    processing_function,
-    input_signals=[left_signal, right_signal],
-    output_signal=output_signal,
+    dlunit=None,
+    file=Path("units/total.dlunit"),
 )
 ```
 
-`function` must define exactly one Python function. Its parameters must be:
+The unit's Python source must define exactly one function. Its parameters must
+be:
 
 1. Zero or more `ValueDescriptor` parameters, in the same order as
-   `input_signals`.
-2. One final `SignalDescriptor` parameter for `output_signal`.
+   the manifest's `input_signals`.
+2. One final `SignalDescriptor` parameter for the manifest's `return_signal`.
 3. A return annotation of `ValueDescriptor`.
 
 The parameter annotations must use the imported `ValueDescriptor` and
@@ -378,8 +404,9 @@ individual failure reason:
 
 | Exception | Area | Codes |
 | --- | --- | --- |
-| `CoreError` | Core lifecycle, mode, and recording operations. | `invalid_state`, `invalid_mode`, `incorrect_mode`, `recording_active`, `not_recording`, `no_recording`, `no_playback_data` |
-| `DLPakError` | Archive preparation, reading, and writing. | `no_data`, `no_manifest`, `read_failed`, `write_failed` |
+| `CoreError` | Core lifecycle, mode, recording, and derive-unit binding operations. | `invalid_state`, `invalid_mode`, `incorrect_mode`, `recording_active`, `not_recording`, `no_recording`, `no_playback_data`, `bind_derive_failed` |
+| `DLPakError` | Recording archive preparation, reading, and writing. | `no_data`, `no_manifest`, `read_failed`, `write_failed` |
+| `DLUnitError` | Derive-unit archive preparation, reading, and writing. | `no_data`, `no_manifest`, `read_failed`, `write_failed` |
 | `DeriveError` | Derive source, signatures, arguments, and registration. | `invalid_source`, `invalid_signature`, `input_signal_mismatch`, `argument_mismatch`, `already_registered` |
 | `PlaybackError` | Playback state and data. | `no_data`, `incomplete_data`, `already_playing`, `invalid_timestamp`, `stopped` |
 | `ConnectorError` | Connector queues and registration. | `queue_full`, `already_registered` |

src/dynalab_core/__init__.py

@@ -19,6 +19,7 @@ from dynalab_core.config import CoreConfig
 from dynalab_core.constants import CORE_VERSION
 from dynalab_core.derive import DeriveRegistry
 from dynalab_core.dlpak import DLPak
+from dynalab_core.dlunit import DLUnit
 from dynalab_core.errors import CoreError
 from dynalab_core.playback import PlaybackEngine
 from dynalab_core.protocols.endpoint import ConnectorRegistry
@@ -300,12 +301,22 @@ class Core:
         return {signal_id: value.get() for signal_id, value in live_values}
 
     def bind_derive_unit(
-        self,
-        function: str,
-        input_signals: list[SignalDescriptor],
-        output_signal: SignalDescriptor,
+        self, dlunit: DLUnit | None = None, file: Path | None = None
     ) -> UUID:
-        unit = self._derive_registry.register(function, input_signals, output_signal)
+        if dlunit is not None and file is not None:
+            raise CoreError(
+                "Bind a derive unit from either a DLUnit or a file, not both",
+                code="bind_derive_failed",
+            )
+        if dlunit is None and file is not None:
+            dlunit = DLUnit().read(file)
+        elif dlunit is None and file is None:
+            raise CoreError(
+                "Cannot bind derive unit with no dlunit OR file specified",
+                code="bind_derive_failed",
+            )
+
+        unit = self._derive_registry.register(dlunit)
         return unit.uuid()
 
     def unbind_derive_unit(self, unit_id: UUID) -> None:

src/dynalab_core/derive.py

@@ -12,6 +12,7 @@ import threading
 import types
 from uuid import UUID, uuid4
 
+from dynalab_core.dlunit import DLUnit
 from dynalab_core.errors import DeriveError
 from dynalab_core.protocols.packets.data import ValueDescriptor
 from dynalab_core.protocols.packets.handshake import SignalDescriptor
@@ -214,17 +215,11 @@ class DeriveRegistry:
         )
         self._routing_worker_thread.start()
 
-    def register(
-        self,
-        function: str,
-        input_signals: list[SignalDescriptor],
-        output_signal: SignalDescriptor,
-        unit_uuid: UUID | None = None,
-    ) -> DeriveUnit:
+    def register(self, dlunit: DLUnit) -> DeriveUnit:
 
-        if unit_uuid is not None:
+        if dlunit._manifest.unit_uuid is not None:
             with self._lock:
-                current = self.get(unit_uuid)
+                current = self.get(dlunit._manifest.unit_uuid)
                 if current is not None:
                     log.warning(
                         "Derive Unit %s is already registered",
@@ -236,14 +231,14 @@ class DeriveRegistry:
                         },
                     )
                     raise DeriveError(
-                        f"Derive unit {unit_uuid} is already registered",
+                        f"Derive unit {dlunit._manifest.unit_uuid} is already registered",
                         code="already_registered",
                     )
-        unit_id = unit_uuid or uuid4()
+        unit_id = dlunit._manifest.unit_uuid or uuid4()
 
         namespace = {}
         try:
-            exec(function, namespace)
+            exec(dlunit._data, namespace)
         except Exception as error:
             raise DeriveError(
                 f"Could not load derive function: {error}",
@@ -261,7 +256,11 @@ class DeriveRegistry:
             )
 
         unit = DeriveUnit(
-            unit_id, functions[0], input_signals, output_signal, self._core_input_queue
+            unit_id,
+            functions[0],
+            dlunit._manifest.input_signals,
+            dlunit._manifest.return_signal,
+            self._core_input_queue,
         )
 
         with self._lock:
@@ -273,8 +272,10 @@ class DeriveRegistry:
             extra={
                 "event": "derive.registered",
                 "derive_uuid": str(unit_id),
-                "input_signal_ids": [str(signal.id) for signal in input_signals],
-                "output_signal_id": str(output_signal.id),
+                "input_signal_ids": [
+                    str(signal.id) for signal in dlunit._manifest.input_signals
+                ],
+                "output_signal_id": str(dlunit._manifest.return_signal.id),
             },
         )
 

src/dynalab_core/dlunit.py

@@ -0,0 +1,142 @@
+# Copyright (C) 2026 Hector van der Aa <hector@h3cx.dev>
+# Copyright (C) 2026 Association Exergie <association.exergie@gmail.com>
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+import logging
+from pathlib import Path
+from typing import Literal, Self
+from uuid import UUID
+from zipfile import ZIP_DEFLATED, ZipFile
+
+from pydantic import BaseModel, Field
+
+from dynalab_core.errors import DLPakError, DLUnitError
+from dynalab_core.protocols.packets.handshake import SignalDescriptor
+
+
+log = logging.getLogger(__name__)
+
+
+class DeriveManifest(BaseModel):
+    unit_uuid: UUID
+    input_signals: list[SignalDescriptor] = Field(default_factory=list)
+    return_signal: SignalDescriptor
+    comments: str = ""
+
+
+class DLUnit:
+    def __init__(self) -> None:
+        self._dir: Path | None = None
+        self._filename: str | None = None
+        self._savetype: Literal["zip", "folder"] = "zip"
+        self._data: str | None = None
+        self._manifest: DeriveManifest | None = None
+
+    def set_data(self, data: str) -> None:
+        self._data = data
+
+    def set_manifest(
+        self,
+        unit_uuid: UUID,
+        input_signals: list[SignalDescriptor],
+        return_signal: SignalDescriptor,
+    ) -> None:
+
+        self._manifest = DeriveManifest(
+            unit_uuid=unit_uuid,
+            input_signals=input_signals,
+            return_signal=return_signal,
+        )
+
+    def read(self, file: str | Path) -> Self:
+        input_path = Path(file)
+
+        try:
+            with ZipFile(input_path, mode="r") as archive:
+                manifest = DeriveManifest.model_validate_json(
+                    archive.read("manifest.json")
+                )
+                data: str = archive.read("unit.py").decode("utf-8")
+        except Exception as error:
+            log.exception(
+                "Failed to read DLUnit archive from %s",
+                input_path.name,
+                extra={
+                    "event": "dlunit.read_failed",
+                    "input_filename": input_path.name,
+                    "exception_type": type(error).__name__,
+                },
+            )
+            raise DLUnitError(
+                f"Could not read DLUnit archive {input_path}: {error}",
+                code="read_failed",
+            ) from error
+
+        self._dir = input_path.parent
+        self._filename = input_path.name
+        self._data = data
+        self._manifest = manifest
+
+        log.info(
+            "Read DLUnit archive from %s",
+            input_path.name,
+            extra={
+                "event": "dlunit.read",
+                "input_filename": input_path.name,
+            },
+        )
+        return self
+
+    def write(self, dir: str | Path, filename: str) -> None:
+        output_dir = Path(dir)
+
+        if self._data is None:
+            raise DLUnitError(
+                "Cannot write a DLUnit archive before setting its data",
+                code="no_data",
+            )
+        if self._manifest is None:
+            raise DLUnitError(
+                "Cannot write a DLUnit archive before creating its manifest",
+                code="no_manifest",
+            )
+
+        if output_dir.is_file():
+            output_dir = output_dir.parent
+
+        file_path = Path(filename)
+
+        if file_path.suffix.lower() != ".dlunit":
+            file_path = file_path.with_suffix(".dlunit")
+
+        output_path = output_dir / file_path
+
+        try:
+            with ZipFile(output_path, mode="w", compression=ZIP_DEFLATED) as archive:
+                archive.writestr(
+                    "manifest.json", self._manifest.model_dump_json(indent=2)
+                )
+                archive.writestr("unit.py", self._data.export_csv())
+        except Exception as error:
+            log.exception(
+                "Failed to write DLUnit archive to %s",
+                output_path.name,
+                extra={
+                    "event": "dlunit.write_failed",
+                    "output_filename": output_path.name,
+                    "exception_type": type(error).__name__,
+                },
+            )
+            raise DLUnitError(
+                f"Could not write DLUnit archive {output_path}: {error}",
+                code="write_failed",
+            ) from error
+
+        log.info(
+            "Wrote DLUnit archive to %s",
+            output_path.name,
+            extra={
+                "event": "dlunit.written",
+                "output_filename": output_path.name,
+            },
+        )

src/dynalab_core/errors.py

@@ -27,6 +27,10 @@ class DLPakError(DynaLabError):
     """A DLPak archive cannot be prepared, read, or written."""
 
 
+class DLUnitError(DynaLabError):
+    """A DLPak archive cannot be prepared, read, or written."""
+
+
 class DeriveError(DynaLabError):
     """A derive unit cannot be created or used as requested."""
 

test/manual/core.py

@@ -7,6 +7,7 @@ from rich.logging import RichHandler
 
 from dynalab_core import Core
 from dynalab_core.config import CoreConfig
+from dynalab_core.dlunit import DLUnit
 from dynalab_core.protocols.packets.handshake import SignalDescriptor
 
 logging.basicConfig(
@@ -29,9 +30,9 @@ log.info("Configured manual core on %s", config.bind_str())
 dl_core = Core(config)
 dl_core.start()
 
-
-unit_id = dl_core.bind_derive_unit(
-    processing_str,
+dl_unit = DLUnit()
+dl_unit.set_manifest(
+    uuid4(),
     [
         SignalDescriptor(
             id=signal_id_1, name="Dummy signal 1", type="number", timeout_ms=5000
@@ -42,6 +43,9 @@ unit_id = dl_core.bind_derive_unit(
     ],
     SignalDescriptor(id=uuid4(), name="Dummy sum", type="number", timeout_ms=5000),
 )
+dl_unit.set_data(processing_str)
+
+unit_id = dl_core.bind_derive_unit(dl_unit)
 
 # for i in range(10):
 #     dl_core.wait(1)

test/manual/core_tui.py

@@ -1,7 +1,9 @@
+from collections import deque
 import logging
 import select
 import sys
 import termios
+from threading import Lock
 import time
 import tty
 from contextlib import contextmanager
@@ -17,6 +19,7 @@ from rich.text import Text
 
 from dynalab_core import Core
 from dynalab_core.config import CoreConfig
+from dynalab_core.dlunit import DLUnit
 from dynalab_core.errors import DynaLabError
 from dynalab_core.protocols.packets.handshake import SignalDescriptor
 
@@ -24,6 +27,8 @@ from dynalab_core.protocols.packets.handshake import SignalDescriptor
 HOST = "127.0.0.1"
 PORT = 8765
 DISPLAY_FREQUENCY_HZ = 5.0
+LOG_HISTORY_SIZE = 1_000
+VISIBLE_LOG_LINES = 12
 
 signal_id_1: UUID = UUID("3f32cea3-d872-4c16-a0a2-54b57171aeb2")
 signal_id_2: UUID = UUID("6578ac37-99d1-410c-b3f7-d049339919b2")
@@ -45,10 +50,59 @@ def keyboard_input() -> Iterator[None]:
         termios.tcsetattr(file_descriptor, termios.TCSADRAIN, previous_settings)
 
 
+class TuiLogHandler(logging.Handler):
+    """Keep recent DynaLab Core log messages available to the live display."""
+
+    def __init__(self) -> None:
+        super().__init__()
+        self._entries: deque[tuple[str, str, str, str]] = deque(
+            maxlen=LOG_HISTORY_SIZE
+        )
+        self._lock = Lock()
+        self.setFormatter(
+            logging.Formatter(
+                "%(asctime)s %(levelname)-8s %(name)s: %(message)s",
+                datefmt="%H:%M:%S",
+            )
+        )
+
+    def emit(self, record: logging.LogRecord) -> None:
+        try:
+            message = record.getMessage().replace("\n", " ↳ ")
+            if record.exc_info is not None and record.exc_info[1] is not None:
+                message = f"{message} ({record.exc_info[1]})"
+            level = record.levelname
+            level_style = {
+                logging.DEBUG: "dim",
+                logging.INFO: "white",
+                logging.WARNING: "yellow",
+                logging.ERROR: "bold red",
+                logging.CRITICAL: "bold white on red",
+            }.get(record.levelno, "white")
+            with self._lock:
+                self._entries.append(
+                    (
+                        self.formatter.formatTime(record, datefmt="%H:%M:%S"),
+                        level,
+                        message,
+                        level_style,
+                    )
+                )
+        except Exception:
+            self.handleError(record)
+
+    def latest(self, limit: int) -> list[tuple[str, str, str, str]]:
+        with self._lock:
+            return list(self._entries)[-limit:]
+
+
 class Dashboard:
-    def __init__(self, core: Core, config: CoreConfig) -> None:
+    def __init__(
+        self, core: Core, config: CoreConfig, log_handler: TuiLogHandler
+    ) -> None:
         self.core = core
         self.config = config
+        self.log_handler = log_handler
         self.running = True
         self.playback_loaded = False
         self.message = "Waiting for a connector"
@@ -170,6 +224,22 @@ class Dashboard:
             "[bold]L[/bold] Load   [bold]Space[/bold] Play/Pause   "
             "[bold]Q[/bold] Quit"
         )
+        log_table = Table.grid(expand=True, padding=(0, 1))
+        log_table.add_column(style="dim", width=8, no_wrap=True)
+        log_table.add_column(width=8, no_wrap=True)
+        log_table.add_column(ratio=1, no_wrap=True, overflow="ellipsis")
+        log_entries = self.log_handler.latest(VISIBLE_LOG_LINES)
+        if log_entries:
+            for timestamp, level, message, style in log_entries:
+                log_table.add_row(
+                    Text(timestamp),
+                    Text(level, style=style),
+                    Text(message, style=style),
+                )
+        else:
+            log_table.add_row("", "", Text("No DynaLab Core logs yet", style="dim"))
+        for _ in range(VISIBLE_LOG_LINES - max(1, len(log_entries))):
+            log_table.add_row("", "", "")
 
         return Group(
             Panel(
@@ -181,6 +251,11 @@ class Dashboard:
             Panel(value_table, title="Live values", border_style="cyan"),
             Panel(Text(self.message, style=self.message_style), title="Status"),
             Panel(controls, title="Hotkeys", border_style="blue"),
+            Panel(
+                log_table,
+                title=f"Logs · latest {VISIBLE_LOG_LINES}",
+                border_style="magenta",
+            ),
         )
 
     def playback_status(self, playing: bool) -> str:
@@ -193,15 +268,23 @@ class Dashboard:
 
 def main() -> None:
     logging.basicConfig(level=logging.CRITICAL)
+    log_handler = TuiLogHandler()
+    dynalab_logger = logging.getLogger("dynalab_core")
+    previous_log_level = dynalab_logger.level
+    previous_propagation = dynalab_logger.propagate
+    dynalab_logger.setLevel(logging.DEBUG)
+    dynalab_logger.propagate = False
+    dynalab_logger.addHandler(log_handler)
     config = CoreConfig(host=HOST, port=PORT)
     core = Core(config)
     processing_source = Path(__file__).with_name("process.py").read_text(
         encoding="utf-8"
     )
-    dashboard = Dashboard(core, config)
+    dashboard = Dashboard(core, config, log_handler)
 
-    core.bind_derive_unit(
-        processing_source,
+    derive_unit = DLUnit()
+    derive_unit.set_manifest(
+        uuid4(),
         [
             SignalDescriptor(
                 id=signal_id_1,
@@ -224,13 +307,15 @@ def main() -> None:
             origin="derived",
         ),
     )
+    derive_unit.set_data(processing_source)
+    core.bind_derive_unit(dlunit=derive_unit, file=None)
 
     try:
         core.start()
         with keyboard_input(), Live(
             dashboard.render(),
             auto_refresh=False,
-            screen=True,
+            screen=False,
         ) as live:
             while dashboard.running:
                 update_started = time.monotonic()
@@ -245,6 +330,9 @@ def main() -> None:
         pass
     finally:
         core.stop()
+        dynalab_logger.removeHandler(log_handler)
+        dynalab_logger.setLevel(previous_log_level)
+        dynalab_logger.propagate = previous_propagation
 
 
 if __name__ == "__main__":

test/test_core.py

@@ -1,14 +1,16 @@
 import logging
+from pathlib import Path
 import threading
 from uuid import uuid4
 
 import pytest
 from dynalab_core import Core
 from dynalab_core.config import CoreConfig
+from dynalab_core.dlunit import DLUnit
 from dynalab_core.errors import CoreError
 from dynalab_core.protocols.endpoint import ConnectorEndpoint
 from dynalab_core.protocols.packets.data import ValueDescriptor
-from dynalab_core.protocols.packets.handshake import ConnectorHello
+from dynalab_core.protocols.packets.handshake import ConnectorHello, SignalDescriptor
 from test.common import find_available_port
 
 
@@ -99,3 +101,34 @@ def test_core_mode_is_shared_with_endpoints() -> None:
         assert raised.value.code == "no_playback_data"
     finally:
         core.stop()
+
+
+def test_core_binds_in_memory_dlunit() -> None:
+    core = Core(CoreConfig(port=find_available_port(8765)))
+    input_signal = SignalDescriptor(id=uuid4(), name="Input", type="number")
+    return_signal = SignalDescriptor(
+        id=uuid4(), name="Output", type="number", origin="derived"
+    )
+    dlunit = DLUnit()
+    dlunit.set_manifest(uuid4(), [input_signal], return_signal)
+    dlunit.set_data(
+        """
+from dynalab_core.protocols.packets.data import ValueDescriptor
+from dynalab_core.protocols.packets.handshake import SignalDescriptor
+
+def identity(value: ValueDescriptor, output: SignalDescriptor) -> ValueDescriptor:
+    return ValueDescriptor(signal_id=output.id, value=value.value, timestamp=value.timestamp)
+"""
+    )
+
+    try:
+        unit_id = core.bind_derive_unit(dlunit)
+        assert core.get_signal_descriptor(return_signal.id) == return_signal
+
+        with pytest.raises(CoreError, match="either a DLUnit or a file") as raised:
+            core.bind_derive_unit(dlunit, file=Path("unit.dlunit"))
+
+        assert raised.value.code == "bind_derive_failed"
+        core.unbind_derive_unit(unit_id)
+    finally:
+        core.stop()

test/test_derive.py

@@ -5,6 +5,7 @@ from uuid import UUID, uuid4
 
 import pytest
 from dynalab_core.derive import DeriveRegistry
+from dynalab_core.dlunit import DLUnit
 from dynalab_core.protocols.packets.data import ValueDescriptor
 from dynalab_core.protocols.packets.handshake import SignalDescriptor
 
@@ -30,6 +31,17 @@ def fail(value: ValueDescriptor, output: SignalDescriptor) -> ValueDescriptor:
 """
 
 
+def make_dlunit(
+    source: str,
+    input_signals: list[SignalDescriptor],
+    return_signal: SignalDescriptor,
+) -> DLUnit:
+    dlunit = DLUnit()
+    dlunit.set_manifest(uuid4(), input_signals, return_signal)
+    dlunit.set_data(source)
+    return dlunit
+
+
 def test_derive_registry_routes_with_live_values() -> None:
     output_queue: Queue[ValueDescriptor] = Queue()
     left_signal = SignalDescriptor(id=uuid4(), name="Left", type="number")
@@ -40,7 +52,11 @@ def test_derive_registry_routes_with_live_values() -> None:
 
     try:
         unit = registry.register(
-            PROCESSING_FUNCTION, [left_signal, right_signal], output_signal
+            make_dlunit(
+                PROCESSING_FUNCTION,
+                [left_signal, right_signal],
+                output_signal,
+            )
         )
         right_value = ValueDescriptor(signal_id=right_signal.id, value=2.0, timestamp=1)
         live_values[right_signal.id] = right_value
@@ -87,7 +103,11 @@ def test_derive_worker_logs_failure_and_stops(
     with caplog.at_level(logging.DEBUG, logger="dynalab_core"):
         try:
             unit = registry.register(
-                FAILING_PROCESSING_FUNCTION, [input_signal], output_signal
+                make_dlunit(
+                    FAILING_PROCESSING_FUNCTION,
+                    [input_signal],
+                    output_signal,
+                )
             )
             unit.put_data(
                 [ValueDescriptor(signal_id=input_signal.id, value=1.0, timestamp=1)]

test/test_errors.py

@@ -8,6 +8,7 @@ import pytest
 from dynalab_core.buffer import ValueBuffer
 from dynalab_core.derive import DeriveRegistry, DeriveUnit
 from dynalab_core.dlpak import DLPak
+from dynalab_core.dlunit import DLUnit
 from dynalab_core.errors import (
     CoreError,
     DLPakError,
@@ -97,7 +98,10 @@ def test_derive_registry_wraps_invalid_source() -> None:
 
     try:
         with pytest.raises(DeriveError, match="Could not load") as raised:
-            registry.register("def broken(", [], output_signal)
+            dlunit = DLUnit()
+            dlunit.set_manifest(uuid4(), [], output_signal)
+            dlunit.set_data("def broken(")
+            registry.register(dlunit)
     finally:
         registry.stop()