Null values can block the analysis
Not sure if this has already been reported (couldn't find a ticket for this issue):
Sending a null value (by mistake) to a port results in a neverending analysis. The following excpert from the AbstractConsumerStages shows why:
final I element = this.getInputPort().receive();
if (null == element) {
returnNoElement();
}
Possible solutions: Check for null values in the pipes, put the elements in a Maybe-similar container, ...