STONReaderError when Using option as #directory: ''

[labordep]

Using this script :

SmalltalkCISpec {
  #loading : [
    SCIMetacelloLoadSpec {
      #baseline : 'MyProject',
      #directory : '',
      #platforms : [ #pharo ]
    }
  ]
}

Does not work because of an error : SmalltalkCISpec is invalid: "STONReaderError: At character 163: ', expected'".

After remove #directory : '', this is ok !

My project have no /src directory :)