Per process containers not working with -with-docker option

[emi80]

Given the example pipeline and configuration below:

// test.nf
process test {
    """
    echo Test 
    """
}

// nextflow.config
process {
    echo = true

    $test.container = 'debian'
}

The following error message is displayed:

$ nextflow run test.nf -with-docker
N E X T F L O W  ~  version 0.12.5
You request to run with Docker but no image has been specified