ECS PlacementConstraint TypeError

I am running troposphere from the latest commit on master. When trying to use ECS PlacementConstraint in a TaskDefinition I get the following error:

TypeError:` <class 'troposphere.ecs.TaskDefinition'>: taskDefinition.PlacementConstraints is <class 'troposphere.ecs.PlacementConstraint'>, expected [<class 'troposphere.ecs.PlacementConstraint'>]

My TaskDefinition looks similar to:

taskDefinition = t.add_resource(TaskDefinition(
    'taskDefinition',
    TaskRoleArn=GetAtt(role, 'Arn'),
    NetworkMode='bridge',
    PlacementConstraints=PlacementConstraint(Type='distinctInstance'),

    ContainerDefinitions=[
        ContainerDefinition(
            Name='service',
            Image=Ref(serviceImage),
            Essential=True,
            MemoryReservation=256,
            PortMappings=[
                PortMapping(
                    ContainerPort=8080,
                    HostPort=80,
                    Protocol='tcp',
                ),
            ],
        ),

[markpeek]

There is a comment here that “distinctInstance is not supported in task definitions”. Which might imply it only works with AWS::ECS::Service.

[markpeek]

I implemented this today and noticed a discrepancy on whether this is a single PlacementConstraint or a list of PlacementConstraint. I implemented it as a list given the other usage in Service. Also, I have a discussion going with the CF team to verify. Try using:

PlacementConstraints=[PlacementConstraint(Type='distinctInstance')],