ERROR: Unexpected symbol when parsing 'setter'

Question

I'm encountering an error while working with a WDL (Workflow Description Language) script. The error message is as follows:

`ERROR: Unexpected symbol (line 8, col 5) when parsing 'setter'.

Expected equal, got "command ".

command {
^

$setter = :equal $e -> $1 `

The issue seems to be related to the command block within one of the tasks in my WDL script. I'm not sure what's causing this error, and I would appreciate any guidance on how to resolve it.

Here's the relevant portion of the WDL script:

wdl

# Define a task named "CreateOutputDirectory."
task CreateOutputDirectory {
    File outputDir
    
    # Input block for the task.
    input {
        File outputDir
    }
    
    command {
        mkdir -p ~{outputDir}  
    }
    
    output {
        File createdOutputDir = "~{outputDir}"  # Define the created output directory as an output.
    }
}

Could someone please help me understand what's causing this error and how to correct it? Your assistance would be greatly appreciated.

Here I also tried two types of command block {} and <<< >>> but no use

    command {
        mkdir -p ~{outputDir}  
    }

AND Alao

    command <<<
        mkdir -p ~{outputDir}  
    >>>