feat: update to 2.4.0

[russkel]

Bug fix

Fixed bug

Fixes #21.

I imagine this work will need to be done for the rush to get the ros2 rolling packages being built on Ubuntu 26.04 for the next ROS2 release.

Fix applied

• Removed old cmake hacks and bump minimum version.
• Works on a source checkout of ros2 rolling on Ubuntu 26.04.

This version of the validator requires a minimum version of nlohmann_json 3.8.0. This seems fine as version 3.11.0 is available in ubuntu 24.04, and 3.12.0 in ubuntu 26.04.

GenAI Use

We follow OSRA's policy on GenAI tools

• I used a GenAI tool in this PR.
• I did not use GenAI

Generated-by:

[mxgrey]

Thanks for this contribution, I'm running into this problem as well while trying to test RMF on Lyrical.

There's just one change needed. I left an inline comment for it. After that we should be able to merge this.

[russkel]

Done.

[mxgrey]

The switch to the newer version of nlohmann_json_schema_validator has changed the way cmake targets are exported, which breaks the cmake scripts of some downstream packages.

This is okay, but it means we should wait until open-rmf/rmf_ros2#520 and open-rmf/rmf_task#137 are approved so we can merge all affected packages simultaneously.

[russkel]

The switch to the newer version of nlohmann_json_schema_validator has changed the way cmake targets are exported, which breaks the cmake scripts of some downstream packages.

This is okay, but it means we should wait until open-rmf/rmf_ros2#520 and open-rmf/rmf_task#137 are approved so we can merge all affected packages simultaneously.

Pretty minor! Would be good to get this in as soon as we can so other downstream packages can get their fixes in.

[mxgrey]

Would be good to get this in as soon as we can so other downstream packages can get their fixes in.

We have a policy that all packages managed by Open-RMF are compatible with each other as source builds from their main branches across all currently supported ROS distros, which includes humble, jazzy, and kilted.

If there are other packages in the ROS ecosystem that depend on this schema validator then we can retarget this PR at a lyrical branch for now and do a quick release into rolling from that branch while we wait for the other PRs to get approved.

[russkel]

Would be good to get this in as soon as we can so other downstream packages can get their fixes in.

We have a policy that all packages managed by Open-RMF are compatible with each other as source builds from their main branches across all currently supported ROS distros, which includes humble, jazzy, and kilted.

If there are other packages in the ROS ecosystem that depend on this schema validator then we can retarget this PR at a lyrical branch for now and do a quick release into rolling from that branch while we wait for the other PRs to get approved.

I had a look at the ros index and it seems only rmf packages are dependencies. Maybe it's just us using it then ;).

[mxgrey]

The situation with nlohmann-json on Lyrical is turning out to be very messy (#Open-RMF PMC (Restricted posting) > Changes for Lyrical need testing @ 💬).

Basically Debian Unstable (and therefore Ubuntu Resolute) is fracturing the package ecosystem between two versions of nlohmann-json which cannot be installed side-by-side. One of those versions is required by pybind11-json-dev which we need for rmf_fleet_adapter_python, but almost all packages in the ecosystem require the other version.

Since there's no telling how long that might take to sort out, there may be a good case for merging this to a lyrical branch and moving forward with a release of only this change on Lyrical.

[luca-della-vedova]

I gave this a try and it seems to fix the issue in Lyrical and not break anything in Humble so I think this is OK? I think the pybind issue will happen regardless of what this package does, pybind11-json is brought by the python fleet adapter in rmf_ros2 and nlohmann-json-dev by the fleet adapter, also in rmf_ros2

[mxgrey]

I gave this a try and it seems to fix the issue in Lyrical and not break anything in Humble

Did you try it with the current main branches of rmf_ros2 and rmf_task? With the changes in this PR, I needed to change the target names used in those repos, like in this PR. Without that I was getting linking failures.

[luca-della-vedova]

Yap, so all the branches together compile and seem to work on humble as well

…

On Thu, 7 May 2026, 5:06 pm Grey, ***@***.***> wrote: *mxgrey* left a comment (open-rmf/nlohmann_json_schema_validator_vendor#22) <#22 (comment)> I gave this a try and it seems to fix the issue in Lyrical and not break anything in Humble Did you try it with the current main branches of rmf_ros2 and rmf_task? With the changes in this PR, I needed to change the target names used in those repos, like in this PR <https://github.com/open-rmf/rmf_task/pull/137/changes#diff-37bd6d445f4f74e975de9ecf004af2d37103502fc0705b4a368684617018a4b3L45>. Without that change the cmake was failing. — Reply to this email directly, view it on GitHub <#22 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ACFQQBVSZ6DCE73HT52YKXT4ZRG25AVCNFSM6AAAAACYKPMQ56VHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHM2DGOJVG4ZDEOBZGE> . Triage notifications on the go with GitHub Mobile for iOS <https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675> or Android <https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub>. You are receiving this because your review was requested.Message ID: ***@***.*** .com>