<project>
  <modelVersion>4..0.0</modelVersion>
  <groupId>org.test</groupId>
  <artifactId>foo</artifactId>
  <version>1.0-SNAPSHOT</version>
  <packaging>jar</packaging>
</project>

[INFO] Scanning for projects...
[ERROR] Internal error: java.lang.NumberFormatException: For input string: "" -> [Help 1]
org.apache.maven.InternalErrorException: Internal error: java.lang.NumberFormatException: For input string: ""
    at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:157)
    at org.apache.maven.cling.invoker.mvn.DefaultMavenInvoker.doExecute(DefaultMavenInvoker.java:496)
    at org.apache.maven.cling.invoker.mvn.DefaultMavenInvoker.execute(DefaultMavenInvoker.java:113)
    at org.apache.maven.cling.invoker.mvn.DefaultMavenInvoker.execute(DefaultMavenInvoker.java:80)
    at org.apache.maven.cling.invoker.LookupInvoker.doInvoke(LookupInvoker.java:235)
    at org.apache.maven.cling.invoker.LookupInvoker.invoke(LookupInvoker.java:210)
    at org.apache.maven.cling.ClingSupport.run(ClingSupport.java:68)
    at org.apache.maven.cling.MavenCling.main(MavenCling.java:51)
    at jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
    at java.lang.reflect.Method.invoke(Method.java:580)
    at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:255)
    at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:201)
    at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:361)
    at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:314)
Caused by: java.lang.NumberFormatException: For input string: ""
    at java.lang.NumberFormatException.forInputString(NumberFormatException.java:67)
    at java.lang.Long.parseLong(Long.java:719)
    at java.lang.Long.valueOf(Long.java:1157)
    at org.apache.maven.internal.impl.model.DefaultModelValidator.compareModelVersions(DefaultModelValidator.java:1967)
    at org.apache.maven.internal.impl.model.DefaultModelValidator.validateModelVersion(DefaultModelValidator.java:1911)
    at org.apache.maven.internal.impl.model.DefaultModelValidator.validateFileModel(DefaultModelValidator.java:367)
    at org.apache.maven.internal.impl.model.DefaultModelBuilder$DefaultModelBuilderSession.doReadFileModel(DefaultModelBuilder.java:1434)
    at org.apache.maven.internal.impl.model.DefaultModelCache$CachingSupplier.get(DefaultModelCache.java:178)
    at org.apache.maven.internal.impl.model.DefaultModelCache.computeIfAbsent(DefaultModelCache.java:65)
    at org.apache.maven.internal.impl.model.DefaultModelCache.computeIfAbsent(DefaultModelCache.java:56)
    at org.apache.maven.internal.impl.model.DefaultModelBuilder$DefaultModelBuilderSession.cache(DefaultModelBuilder.java:1734)
    at org.apache.maven.internal.impl.model.DefaultModelBuilder$DefaultModelBuilderSession.readFileModel(DefaultModelBuilder.java:1239)
    at org.apache.maven.internal.impl.model.DefaultModelBuilder$DefaultModelBuilderSession.loadFilePom(DefaultModelBuilder.java:733)
    at org.apache.maven.internal.impl.model.DefaultModelBuilder$DefaultModelBuilderSession.loadFromRoot(DefaultModelBuilder.java:711)
    at org.apache.maven.internal.impl.model.DefaultModelBuilder$DefaultModelBuilderSession.buildBuildPom(DefaultModelBuilder.java:658)
    at org.apache.maven.internal.impl.model.DefaultModelBuilder$1.build(DefaultModelBuilder.java:226)
    at org.apache.maven.project.DefaultProjectBuilder$BuildSession.build(DefaultProjectBuilder.java:497)
    at org.apache.maven.project.DefaultProjectBuilder$BuildSession.lambda$doBuild$5(DefaultProjectBuilder.java:474)
    at java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:197)
    at java.util.Collections$2.tryAdvance(Collections.java:5073)
    at java.util.Collections$2.forEachRemaining(Collections.java:5081)
    at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:509)
    at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:499)
    at java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:921)
    at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
    at java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:682)
    at org.apache.maven.project.DefaultProjectBuilder$BuildSession.doBuild(DefaultProjectBuilder.java:476)
    at org.apache.maven.project.DefaultProjectBuilder$BuildSession.build(DefaultProjectBuilder.java:450)
    at org.apache.maven.project.DefaultProjectBuilder.build(DefaultProjectBuilder.java:184)
    at org.apache.maven.project.collector.DefaultProjectsSelector.selectProjects(DefaultProjectsSelector.java:61)
    at org.apache.maven.project.collector.RequestPomCollectionStrategy.collectProjects(RequestPomCollectionStrategy.java:49)
    at org.apache.maven.graph.DefaultGraphBuilder.getProjectsForMavenReactor(DefaultGraphBuilder.java:364)
    at org.apache.maven.graph.DefaultGraphBuilder.build(DefaultGraphBuilder.java:100)
    at org.apache.maven.DefaultMaven.buildGraph(DefaultMaven.java:629)
    at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:250)
    at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:225)
    at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:149)
    at org.apache.maven.cling.invoker.mvn.DefaultMavenInvoker.doExecute(DefaultMavenInvoker.java:496)
    at org.apache.maven.cling.invoker.mvn.DefaultMavenInvoker.execute(DefaultMavenInvoker.java:113)
    at org.apache.maven.cling.invoker.mvn.DefaultMavenInvoker.execute(DefaultMavenInvoker.java:80)
    at org.apache.maven.cling.invoker.LookupInvoker.doInvoke(LookupInvoker.java:235)
    at org.apache.maven.cling.invoker.LookupInvoker.invoke(LookupInvoker.java:210)
    at org.apache.maven.cling.ClingSupport.run(ClingSupport.java:68)
    at org.apache.maven.cling.MavenCling.main(MavenCling.java:51)
    at jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
    at java.lang.reflect.Method.invoke(Method.java:580)
    at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:255)
    at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:201)
    at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:361)
    at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:314)
[ERROR] 
[ERROR] To see the full stack trace of the errors, re-run Maven with the '-e' switch
[ERROR] Re-run Maven using the '-X' switch to enable verbose output
[ERROR] 
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/InternalErrorException