Jenkins Pipeline Fails if Step is Unstable

Whatever the step is UNSTABLE or FAILED, the final build result in your script will be FAILED.

You can add propagate to false by default to avoid fail the flow.

def result = build job: 'test', propagate: false

In the end of the flow, you can verdict the final result based on what you got from the "result" variable.

For example

currentBuild.result='UNSTABLE'

Here is a detail example How to set current build result in Pipeline

Lessons learned:

• Jenkins will continuously update the pipeline according to the currentBuild.result value which can be either SUCCESS, UNSTABLE or FAILURE (source).
• The result of build job: <JOBNAME> can be stored in a variable. The build status is in variable.result.
• build job: <JOBNAME>, propagate: false will prevent the whole build from failing right away.
• currentBuild.result can only get worse. If that value was previously FAILED and receives a new status SUCCESS through currentBuild.result = 'SUCCESS' it will stay FAILED

This is what I finally used:

    node {
        def result  // define the variable once in the beginning
        stage 'Unit/SQL-Tests'
        parallel (
           phase1: { result = build job: 'Unit', propagate: false }, // might be UNSTABLE
           phase2: { build 'SQL-Tests' }
        )
        currentBuild.result = result.result  // update the build status. jenkins will update the pipeline's current status accordingly
        stage 'Install SQL'
        build 'InstallSQL'
        stage 'Deploy/Integration-Tests'
        parallel (
           phase1: { build 'Deploy' },
           phase2: { result = build job: 'Integration-Tests', propagate: false }
        )
        currentBuild.result = result.result // should the Unit-Test be FAILED and Integration-Test SUCCESS, then the currentBuild.result will stay FAILED (it can only get worse)
        stage 'Code Analysis'
        build 'Analysis'
    }