Pipeline milestone step has two optional parameters:

ordinal number
label

stage ("Build") {
milestone()
}

works fine in Pipeline script but will fail without an ordinal value in Declarative Pipeline.

Started by user Admin
org.codehaus.groovy.control.MultipleCompilationErrorsException: startup failed:
WorkflowScript: 5: Missing required parameter: 'ordinal' @ line 5, column 13.
milestone()
^

WorkflowScript: 10: Missing required parameter: 'ordinal' @ line 10, column 13.
milestone (label: 'Test')
^

WorkflowScript: 15: Missing required parameter: 'ordinal' @ line 15, column 13.
milestone (label: 'Deploy')
^

3 errors

at org.codehaus.groovy.control.ErrorCollector.failIfErrors(ErrorCollector.java:310)
at org.codehaus.groovy.control.CompilationUnit.applyToPrimaryClassNodes(CompilationUnit.java:1073)
at org.codehaus.groovy.control.CompilationUnit.doPhaseOperation(CompilationUnit.java:591)
at org.codehaus.groovy.control.CompilationUnit.processPhaseOperations(CompilationUnit.java:569)
at org.codehaus.groovy.control.CompilationUnit.compile(CompilationUnit.java:546)
at groovy.lang.GroovyClassLoader.doParseClass(GroovyClassLoader.java:298)
at groovy.lang.GroovyClassLoader.parseClass(GroovyClassLoader.java:268)
at groovy.lang.GroovyShell.parseClass(GroovyShell.java:688)
at groovy.lang.GroovyShell.parse(GroovyShell.java:700)
at org.jenkinsci.plugins.workflow.cps.CpsGroovyShell.reparse(CpsGroovyShell.java:67)
at org.jenkinsci.plugins.workflow.cps.CpsFlowExecution.parseScript(CpsFlowExecution.java:411)
at org.jenkinsci.plugins.workflow.cps.CpsFlowExecution.start(CpsFlowExecution.java:374)
at org.jenkinsci.plugins.workflow.job.WorkflowRun.run(WorkflowRun.java:220)
at hudson.model.ResourceController.execute(ResourceController.java:98)
at hudson.model.Executor.run(Executor.java:410)
Finished: FAILURE