We have a pipeline setup that looks something like this:

pipeline {
    agent any
    stages {
        stage('Initial stage') {
            # Failure will occur here
        }
        stage('Parallel Stage') {
            failFast true
            parallel {
                stage('Branch A') {
                     #stuff
                }
                stage('Branch B') {
                    #stuff
                }
            }
        }
    }
}

As I've indicated, let's say an error occurs in the Initial stage. Our expectation is then that the parallel stages that follow would be set to NOT_BUILT. Instead, they are reported as failures.

My suspicion is that this could be because of the failFast that is used. However, I would argue that this should not be the expected behaviour.

I would very much appreciate some clarification: either why my expectation is wrong, or if this is indeed a bug that should be addressed.