Climate BDA 5.1 is still built against UniversalCohorts-v1 despite release notes claiming v2

[JimmyKeeee]

Summary

Climate BDA is built against Landis.Library.UniversalCohorts-v1, but the
current Core v8 releases of Biomass Succession, Dynamic Fuel System, Dynamic
Fire System and Original Wind are all built against
Landis.Library.UniversalCohorts-v2. Because the two DLLs publish types under
the same namespace but different assembly identities, the Core's site-variable
type check fails at initialization and the run aborts. There is no combination
of current releases in which Climate BDA and Biomass Succession both load.

Error

The data type of site variable "Succession.UniversalCohorts" is
Landis.Library.UniversalCohorts.SiteCohorts, not
Landis.Library.UniversalCohorts.SiteCohorts

The message looks self-contradictory because it prints only the fully-qualified
type name and not the assembly. SiteCohorts from UniversalCohorts-v1.dll and
SiteCohorts from UniversalCohorts-v2.dll are distinct CLR types.

Environment

Component	Version
LANDIS-II Core	8.0 (8)
Biomass Succession	7.2
Dynamic Fuel System	4.1
Dynamic Fire System	4.1
Original Wind	4.1
Climate BDA	5.0
OS	Windows 10

Where it fails

The scenario loads Core, ecoregions, species, Biomass Succession, Dynamic Fuel,
Dynamic Fire and Original Wind successfully. Biomass Succession registers the
site variable:

   Registering Data:  Succession.UniversalCohorts.

Every other extension initializes without complaint. The run then aborts at the
point Climate BDA resolves that variable — after Original Wind finishes
initializing, before any timestep executes.

Root cause in this repository

At tag v5.1, both the project file and the support-library script still pin v1:

• src/BDA-Climate.csproj — <Reference Include="Landis.Library.UniversalCohorts-v1">
• src/lib/support_libs_download.ps1 — downloads Landis.Library.UniversalCohorts-v1.dll

The v5.1 release (2026-05-05, asset LANDIS-II-V8.Climate.BDA.5.1-setup.exe)
is titled "Beta release for changes integrating Universal Cohort Library v2",
but as far as I can tell from the two files above the v2 migration has not
actually landed. If I have misread that and v5.1 is expected to work, please say
so and I will retest against it directly.

Why this cannot be worked around by the user

Downgrading is not an option in the other direction either: no Biomass
Succession release targeting Core v8 is built against UniversalCohorts-v1, so
there is no pair of released binaries that satisfies both sides. The fix has to
be a Climate BDA build against v2.

Steps to reproduce

1. Install LANDIS-II Core v8 with Biomass Succession 7.2, Dynamic Fuel System
   4.1, Dynamic Fire System 4.1, Original Wind 4.1 and Climate BDA 5.0.
2. Run any scenario whose DisturbanceExtensions list includes both
   "Biomass Succession" and "Climate BDA".
3. The run aborts during initialization with the error above.

Removing the "Climate BDA" line and its input file is sufficient to make the
same scenario run to completion, which isolates the failure to that extension.

Request

Is a Climate BDA build against Landis.Library.UniversalCohorts-v2 planned, and
is there a timeline? Happy to test a build against the reproduction scenario
above if that is useful.

[Klemet]

There is actually a commit with the update for UCL2, but it is on a stale branch; I had trouble finding it too ! See 273e938 . You can use it to build. We've just deployed it in https://github.com/LANDIS-II-Foundation/Tool-Docker-Apptainer, and it works great !

[JimmyKeeee]

There is actually a commit with the update for UCL2, but it is on a stale branch; I had trouble finding it too ! See 273e938 . You can use it to build. We've just deployed it in https://github.com/LANDIS-II-Foundation/Tool-Docker-Apptainer, and it works great !

Thank you very much!