The docs mention the need for all data in steps to be serializable, but it doesn't mention that it somehow breaks Groovy maps in order to do.

If I run

def map =  [foo: "bar", test: 'hello']

println 'Using Groovy version ' + GroovySystem.getVersion()
println map

map.each { k, v -> println "$k := $v" }

I will see the following when I run groovy locally:

Using Groovy version 1.8.9
[foo:bar, test:hello]
foo := bar
test := hello

However, I'll get this output from the Jenkins workflow plugin: (note that the each() iteration only shows the first element, and it is not a key/value pair

Using Groovy version 1.8.9
Running: Print Message
{foo=bar, test=hello}
Running: Print Message
foo=bar := null

If this is expected behavior, it means users cannot use maps as expected, unless specifically passed to workflow classes that know how to read those parameters.

Am I doing something wrong here, or should the docs just be updated to reflect this?