How to get the incoming changes from a remote Mercurial repository with javahg?

Question

I'm trying to write a sample program that uses javahg to get information on a project repository. I'm running on a Windows client and the remote repository is on a Linux Server. However, when I try to get the incoming changes, it hangs or it gives me a null bundle as a result.

class Mercurial {

static void main(String[] args) {
    def projectDir = 'c:/my-workbench/my-project'

    RepositoryConfiguration repoConfig = new RepositoryConfiguration()
    repoConfig.hgBin = 'c:/Program Files/TortoiseHg/hg.exe'
    repoConfig.sshBin = 'c:/opt/putty/plink.exe'

    repoConfig.hgrcPath = null 
    //repoConfig.hgrcPath = 'c:/users/david/mercurial.ini' //nothing changes

    def localRepo = Repository.open(repoConfig, new File(projectDir))

    IncomingCommand incoming = IncomingCommand.on(localRepo)

    //this is the content of the HGRC file in the .hg folder
    def remoteRepoURL = 'ssh://hg@9.9.9.9/my-project')

    def bundle = incoming.execute(remoteRepoURL)
}

Instead, if I clone the remote repository everything is fine, so the configuration should be correct.

    BaseRepository br = BaseRepository.clone(repoConfig, new File('c:/temp/local'), remoteRepoURL)

How can I get the incoming changes from a remote repository?