NPE in karaf-maven-plugin when specifying descriptor by file url

[ERROR] Failed to execute goal org.apache.karaf.tooling:karaf-maven-plugin:4.1.2:features-add-to-repository (features-add-to-repository) on project myProject: Error populating repository: NullPointerException -> [Help 1]
org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal org.apache.karaf.tooling:karaf-maven-plugin:4.1.2:features-add-to-repository (features-add-to-repository) on project myProject: Error populating repository
	at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:212)
	at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:153)
	at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:145)
	at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:116)
	at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:80)
	at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build(SingleThreadedBuilder.java:51)
	at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:128)
	at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:307)
	at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:193)
	at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:106)
	at org.apache.maven.cli.MavenCli.execute(MavenCli.java:863)
	at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:288)
	at org.apache.maven.cli.MavenCli.main(MavenCli.java:199)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:289)
	at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:229)
	at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:415)
	at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:356)
Caused by: org.apache.maven.plugin.MojoExecutionException: Error populating repository
	at org.apache.karaf.tooling.features.AbstractFeatureMojo.resolveFeatures(AbstractFeatureMojo.java:267)
	at org.apache.karaf.tooling.features.AddToRepositoryMojo.execute(AddToRepositoryMojo.java:58)
	at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:134)
	at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:207)
	... 20 more
Caused by: java.lang.NullPointerException
	at org.apache.karaf.tooling.features.AbstractFeatureMojo.retrieveDescriptorsRecursively(AbstractFeatureMojo.java:125)
	at org.apache.karaf.tooling.features.AbstractFeatureMojo.resolveFeatures(AbstractFeatureMojo.java:236)
	... 23 more

<plugin>
    <groupId>org.apache.karaf.tooling</groupId>
    <artifactId>karaf-maven-plugin</artifactId>
    <executions>
        <execution>
            <id>features-add-to-repository</id>
            <phase>prepare-package</phase>
            <goals>
                <goal>features-add-to-repository</goal>
            </goals>
            <configuration>
                <addTransitiveFeatures>false</addTransitiveFeatures>
                <descriptors>
                    <descriptor>file:${basedir}/target/classes/${project.artifactId}-features.xml</descriptor>
                </descriptors>
                <repository>${setup.folder}/${karaf.folder}/system</repository>
            </configuration>
        </execution>
    </executions>
</plugin>