cromwell works, caper doesn't

[mapostolides]

Hello, I'm running a basic test script and I'm getting the following error:

caper run test2.wdl

2022-07-25 11:19:48,827|caper.cromwell|INFO| Workflow failed. Auto-troubleshooting...
* Started troubleshooting workflow: id=10ce604e-106b-4490-98c2-21cc4a38ad69, status=Failed
* Found failures JSON object.
[
    {
        "causedBy": [
            {
                "message": "Task hello has an invalid runtime attribute memory = !! NOT FOUND !!",
                "causedBy": []
            }
        ],
        "message": "Runtime validation failed"
    }
]

However, when I run it with cromwell directly I get no such error:

java -jar cromwell-65.jar run test2.wdl

4074aa71b [1d5b6b64]: Workflow myWorkflow complete. Final Outputs:
{
  "myWorkflow.myTask.out": "hello world"
}

The WDL script I'm using is as follows:

workflow myWorkflow {
    call myTask
}

task myTask {
    command {
        echo "hello world"
    }
    output {
        String out = read_string(stdout())
    }
}