xsd-dependency-tree hangs with xsd's that import each other

[mywill]

I have been having a issue with importing some XSDs into my project, that i'm converting from maven, where the xsd to java task just hangs. I was able to recreate the issue with the following sample project. It may be related to #20 .

Using a mac running 10.13.1, gradle 4.6, version 2.4.1 of the plugin, and java 1.8.0_131, the following gradle file and xsd's the xsd-dependency-tree never seems to end and uses 100% of 1 cpu.

plugins {
    id "org.openrepose.gradle.plugins.jaxb" version "2.4.1"
}

repositories {
    mavenCentral()
}

jaxb {
    xsdDir = "${project.projectDir}/src/main/xsd"
    xjc {
        destinationDir = "${project.buildDir}/generated-sources/"
        generateEpisodeFiles = false
    }
}
dependencies {
    jaxb 'com.sun.xml.bind:jaxb-xjc:2.2.11'
    jaxb 'com.sun.xml.bind:jaxb-impl:2.2.11'
    jaxb 'javax.xml.bind:jaxb-api:2.2.11'
}

<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema" targetNamespace="xsd-cross-import-1-namespace">
    <xsd:import namespace="xsd-cross-import-2-namespace"
                schemaLocation= "xsd-cross-import-2.xsd"/>
    <xsd:element name="messageRequest">
        <xsd:complexType>
            <xsd:sequence>
                <xsd:element name="thing" type="xsd:string"/>
            </xsd:sequence>
        </xsd:complexType>
    </xsd:element>
    <xsd:element name="messageResponse" type="xsd:boolean"/>
    <xsd:element name="messageFault" type="xsd:string"/>
</xsd:schema>

<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema" targetNamespace="xsd-cross-import-2-namespace">
     <xsd:import namespace="xsd-cross-import-1-namespace"
                 schemaLocation= "xsd-cross-import-1.xsd"/>
     <xsd:element name="messageRequest">
         <xsd:complexType>
             <xsd:sequence>
                 <xsd:element name="thing2" type="xsd:string"/>
             </xsd:sequence>
         </xsd:complexType>
     </xsd:element>
 </xsd:schema>

The process produces the following logs on INFO

Initialized native services in: /Users/user/.gradle/native
Removing 0 daemon stop events from registry
Starting a Gradle Daemon (subsequent builds will be faster)
Starting process 'Gradle build daemon'. Working directory: /Users/user/.gradle/daemon/4.6 Command: /Library/Java/JavaVirtualMachines/jdk1.8.0_131.jdk/Contents/Home/bin/java -XX:+HeapDumpOnOutOfMemoryError -Xmx1024m -Dfile.encoding=UTF-8 -Duser.country=US -Duser.language=en -Duser.variant -cp /Users/user/.gradle/wrapper/dists/gradle-4.6-bin/4jp4stjndanmxuerzfseyb6wo/gradle-4.6/lib/gradle-launcher-4.6.jar org.gradle.launcher.daemon.bootstrap.GradleDaemon 4.6
Successfully started process 'Gradle build daemon'
An attempt to start the daemon took 1.014 secs.
The client will now receive all logging from the daemon (pid: 3389). The daemon log file: /Users/user/.gradle/daemon/4.6/daemon-3389.out.log
Starting build in new daemon [memory: 954.7 MB]
Using 8 worker leases.
Starting Build
Compiling settings file '/Users/user/Code/test-xsd-parse/settings.gradle' using SubsetScriptTransformer.
Compiling settings file '/Users/user/Code/test-xsd-parse/settings.gradle' using BuildScriptTransformer.
Settings evaluated using settings file '/Users/user/Code/test-xsd-parse/settings.gradle'.
Projects loaded. Root project using build file '/Users/uesr/Code/test-xsd-parse/build.gradle'.
Included projects: [root project 'test-xsd-parse']

> Configure project : 
Evaluating root project 'test-xsd-parse' using build file '/Users/user/Code/test-xsd-parse/build.gradle'.
Compiling build file '/Users/user/Code/test-xsd-parse/build.gradle' using SubsetScriptTransformer.
Compiling build file '/Users/user/Code/test-xsd-parse/build.gradle' using BuildScriptTransformer.

All projects evaluated.
Selected primary task 'xjc' from project :
Tasks to be executed: [task ':xsd-dependency-tree', task ':xjc']
:xsd-dependency-tree (Thread[Task worker for ':' Thread 4,5,main]) started.

> Task :xsd-dependency-tree 
Task ':xsd-dependency-tree' is not up-to-date because:
  Task has not declared any outputs.
jaxb: starting Namespace Task
resolving(grouping) '2' documents by their unique namespaces
resolving external dependencies for namespaces '[xsd-cross-import-1-namespace, xsd-cross-import-2-namespace]'
jaxb: generating xsd namespace dependency tree
creating baseNamespaces '0' as tree nodes
<-------------> 0% EXECUTING [5m 45s]
> :xsd-dependency-tree

Attached are the debug log and the sample project i used to recreate this issue
debuglog.txt
test-xsd-parse.zip

[wdschei]

Thanks for the info on this @mywill. Based on this analysis, I too believe this is probably the same root cause as #20. We are actually getting ready to start some more updates to this plugin and specifically dealing with the xsd-dependency-tree task. I will take a closer look at this then and keep you posted.