# Incompatible dimension universe versions - database universe (r30+)

**URL:** <https://www.rubin.community/t/incompatible-dimension-universe-versions-database-universe-r30/12456>\
**Category:** Data Products\
**Tags:** butler\
**Created:** [August 13, 2026, 9:03am UTC](https://www.rubin.community/t/incompatible-dimension-universe-versions-database-universe-r30/12456 "2026-08-13T09:03:50Z")\
**Posts on this page:** 6\
**Page:** 1

<div class="post-metadata">

**Author:** ![Mandy8808](https://sea2.discourse-cdn.com/flex002/user_avatar/www.rubin.community/mandy8808/32/4019_2.png) [@Mandy8808](https://www.rubin.community/u/Mandy8808)\
**Post date:** [August 13, 2026, 9:03am UTC](https://www.rubin.community/t/incompatible-dimension-universe-versions-database-universe-r30/12456/1 "2026-08-13T09:03:50Z")

</div>

Hi,

Recently I developed a pipeline to work with modified injected stamps. The pipeline works correctly with releases prior to **r30** (e.g. **r29** ).

The problem appears when I try to create a local repository. During the transfer process, when the pipeline reaches the step:

**\> Registering DatasetType ‘skyMap’ in local repo before transfer.**

I get the following error:

```nohighlight
ValueError: Incompatible dimension universe versions - database universe: DimensionUniverse(8, daf_butler), dataset type universe: DimensionUniverse(7, daf_butler).

```

To check whether this was an issue with my code, I ran exactly the same notebook using the latest **r29** release, and everything worked as expected. This makes me think that the problem is related to changes introduced in **r30** , possibly involving the Butler dimension universe or dataset type compatibility.

Has anyone encountered this issue before, or is there any migration step required when creating a local repository with r30+? Any suggestions would be greatly appreciated.

Thank you!

---

<div class="post-metadata">

**Author:** ![timj](https://sea2.discourse-cdn.com/flex002/user_avatar/www.rubin.community/timj/32/10_2.png) [@timj](https://www.rubin.community/u/timj)\
**Post date:** [August 13, 2026, 4:33pm UTC](https://www.rubin.community/t/incompatible-dimension-universe-versions-database-universe-r30/12456/2 "2026-08-13T16:33:01Z")

</div>

If you are creating the local repository using v30 from a DP1 butler this should work since I fixed a bug for exactly that issue in v30.0.10 (there was a DP1 tutorial notebook doing this). Can you give me more explicit instructions on how to reproduce?

---

<div class="post-metadata">

**Author:** ![Mandy8808](https://sea2.discourse-cdn.com/flex002/user_avatar/www.rubin.community/mandy8808/32/4019_2.png) [@Mandy8808](https://www.rubin.community/u/Mandy8808)\
**Post date:** [August 13, 2026, 9:11pm UTC](https://www.rubin.community/t/incompatible-dimension-universe-versions-database-universe-r30/12456/3 "2026-08-13T21:11:26Z")

</div>

Dear Tim,

Thank you for your reply, and I apologize for not providing enough information.

The error appears in the following environment:

- **Release:** r30.0.10 (RSP Build 2991)
- **lsst\_distrib:** `gdfb3db0272+4407f27008` (`current`, `o_latest`, `v30_0_10`, `v30_0_10_rc4`)
- **Python:** 3.13.9

And yes, I’m using the **LSSTComCam/DP1** collection.

The error originates from the following function:

```python
def reg_transfer_skyMap(self, remote_collection: str = "LSSTComCam/DP1") -> None:
    """
    First: Registering SkyMap DatasetType and copying skyMap dataset(s)
    (preserving UUIDs). Ensure skyMap DatasetType exists locally so
    transfer-datasets can attach refs.

    Second: Transfer skyMap(s).
    """
    remote_butler = Butler(self.remote_repo, collections=remote_collection)
    remote_dt = [dt for dt in remote_butler.registry.queryDatasetTypes()
                 if dt.name == "skyMap"]

    if remote_dt:
        self.logger.info("Registering DatasetType 'skyMap' in local repo before transfer.")
        register_datasetTypes(self.local_repo, remote_dt, logger=self.logger)
    else:
        self.logger.warning("Remote repo does NOT contain datasetType 'skyMap'.")
        raise

    try:
        self.logger.info("Copying skyMap(s) from remote to local (preserving UUIDs)...")
        skymap_register_from_remote(
            self.remote_repo,
            self.local_repo,
            remote_collections=remote_collection,
            logger=self.logger,
        )
        self.logger.info("SkyMap copy finished.")
    except Exception:
        self.logger.exception("SkyMap copy failed.")
        raise

```

More specifically, the exception is raised at:

```python
register_datasetTypes(self.local_repo, remote_dt, logger=self.logger)

```

where I get:

```nohighlight
ValueError: Incompatible dimension universe versions - database universe: DimensionUniverse(8, daf_butler), dataset type universe: DimensionUniverse(7, daf_butler).

```

The same code works correctly with r29, so I suspect this is related to a change in the Butler dimension universe between r29 and r30. Does `register_datasetTypes` require any changes in r30, or is there now a different recommended way to register dataset types from a remote repository?

Thank you for your help.

---

<div class="post-metadata">

**Author:** ![timj](https://sea2.discourse-cdn.com/flex002/user_avatar/www.rubin.community/timj/32/10_2.png) [@timj](https://www.rubin.community/u/timj)\
**Post date:** [August 15, 2026, 4:07am UTC](https://www.rubin.community/t/incompatible-dimension-universe-versions-database-universe-r30/12456/4 "2026-08-15T04:07:53Z")

</div>

You have your own API wrappers so it’s hard for me to say exactly what you are doing but if you are trying to register a dataset type from one butler in another butler and they do not have identical dimension universes you need to conform the source to the destination. Something like:

```python
 butler.registry.registerDatasetType(dataset_type.conform_to(butler.dimensions))

```

If you use `dest_butler.transfer_from()` then this is all handled for you, including registering of dataset types and dimension records.

If you are running a pipeline task you can also use `executor.use_local_butler(local_repo_path)` to copy what you need from the graph into a local butler (see DP1 tutorial 105\_6).

---

<div class="post-metadata">

**Author:** ![Mandy8808](https://sea2.discourse-cdn.com/flex002/user_avatar/www.rubin.community/mandy8808/32/4019_2.png) [@Mandy8808](https://www.rubin.community/u/Mandy8808)\
**Post date:** [August 17, 2026, 3:14pm UTC](https://www.rubin.community/t/incompatible-dimension-universe-versions-database-universe-r30/12456/5 "2026-08-17T15:14:43Z")

</div>

Thanks, this is very helpful. I think I understand where the problem is now.

In my wrapper I create a new local Butler repository and then manually register the DatasetTypes before transferring the datasets. In particular, I currently have something like:

```python
def register_datasetTypes(local_repo, datasettypes, ...):
    lbutler = Butler(local_repo, writeable=True)
    lreg = lbutler.registry

    for dt in datasettypes:
        lreg.registerDatasetType(dt)

```

The `DatasetType` objects in this case come directly from the remote Butler. Therefore, I think this is exactly where the dimension-universe mismatch occurs: I am trying to register the remote `DatasetType` directly into the newly created local Butler.

Based on your suggestion, I think the minimal fix should be:

```python
for dt in datasettypes:
    local_dt = dt.conform_to(lbutler.dimensions)
    lreg.registerDatasetType(local_dt)

```

At the moment, after this manual registration I use `butler transfer-datasets` to transfer the actual datasets and preserve their UUIDs.

I also see your point about using `dest_butler.transfer_from()` instead. It seems that this could simplify my wrapper considerably, since I would not need to manually register the DatasetTypes and dimension records before the transfer.

I will first test the `conform_to()` change to confirm that this is the source of the r30 problem, and then I will look at replacing part of my manual transfer logic with `transfer_from()`.

Thanks also for pointing me to `executor.use_local_butler()`. My current code is a more general wrapper for constructing a local Butler before running the pipeline, but I will check tutorial 105\_6 as well.

---

<div class="post-metadata">

**Author:** ![Mandy8808](https://sea2.discourse-cdn.com/flex002/user_avatar/www.rubin.community/mandy8808/32/4019_2.png) [@Mandy8808](https://www.rubin.community/u/Mandy8808)\
**Post date:** [August 17, 2026, 3:25pm UTC](https://www.rubin.community/t/incompatible-dimension-universe-versions-database-universe-r30/12456/6 "2026-08-17T15:25:43Z")

</div>

Hi again!,

I tested the change you recommended, using `dataset_type.conform_to(local_butler.dimensions)` before registering the `DatasetType` , and it solved the problem. The dimension universe mismatch disappeared, so that was indeed the issue. Thanks for pointing me in the right direction!

I will also take a closer look at your recommendation of using `dest_butler.transfer_from()` . It seems like a much cleaner approach than my current implementation, so I’ll evaluate whether I can simplify my wrapper around it.

Thanks again for your help. I really appreciate it.