Groovy's Path.traverse() extension, IntelliJ idea syntactic error

Question

I am editing a Groovy (3.0.10) script and I am getting a syntactic error that I do not understand:

When I try this in GroovyConsole, it seems to work just fine.

Why is IntelliJ IDEA complaining? This is with IntelliJ IDEA 2022.1.1.

The snippet in text:

final java.nio.file.Path p;
p.traverse(type: FileType.FILES, nameFilter: ~/^\.deployment$/, maxDepth: 1) { final Path dotDeploymentPath ->
    println dotDeploymentPath
}

UPDATE 1

I actually got the same error from Groovy when running the script in our product:

Script4.groovy: 59: [Static type checking] - Cannot call java.nio.file.Path#traverse(java.util.Map <java.lang.String, java.lang.Object>, groovy.lang.Closure) with arguments [java.util.LinkedHashMap <java.lang.String, java.io.Serializable>, groovy.lang.Closure]
 @ line 59, column 9.
           extensionsPath.traverse(type: FileType.FILES, nameFilter: ~/^\.deployment$/, maxDepth: 1) { final Path dotDeploymentPath ->
           ^

UPDATE 2

I ended up with this which seems to work just fine. I still don't understand why Groovy does not like the options as arguments of the call.

def final traverseOptions = [type: FileType.FILES, nameFilter: ~/^\.deployment$/, maxDepth: 1] as Map<String, Object>;
extensionsPath.traverse(traverseOptions) { final Path dotDeploymentPath ->

Answer 1

To ensure sequential execution of functions, run the functions in a single goroutine:

go func() {
    func1()
    func2()
}()

Answer 2

If you really want them as separate goroutines (why?) you need to synchronize them. You can use channels, mutexes, or other concurrency primitives. The example below accomplishes that with a signaling channel:

ch := make(chan struct{})
go func() {
  func1()
  close(ch)
}
go func() {
  <-ch
  func2()
}

Playground: https://go.dev/play/p/ZqHz-ILpA2J

EDIT: Following Paul Hankin's advice, using close(ch) instead of ch <- struct{}{} to signal completion.