Error during maven "clean install" with plug-in resolve - maven

Question

I try to to use clean install in Maven and get the error below. I have two questions:
Is this an error to be solved with a fair amount of work or is it such an esoteric error, that any attempt to solve it would end up in a long-term project?
Has anybody a solution in mind?
I can provide further info, if necessary. The java version is:
openjdk version "10.0.1" 2018-04-17
I'm running this on Ubuntu 18.04.
WARNING: An illegal reflective access operation has occurred
WARNING: Illegal reflective access by com.google.inject.internal.cglib.core.$ReflectUtils$1 (file:/usr/share/maven/lib/guice.jar) to method java.lang.ClassLoader.defineClass(java.lang.String,byte[],int,int,java.security.ProtectionDomain)
WARNING: Please consider reporting this to the maintainers of com.google.inject.internal.cglib.core.$ReflectUtils$1
WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations
WARNING: All illegal access operations will be denied in a future release
[INFO] Scanning for projects...
[INFO] ------------------------------------------------------------------------
[INFO] Reactor Build Order:
[INFO]
[INFO] DeepLearning4j Examples Parent
[INFO] DeepLearning4j Examples
[INFO] dl4j-spark-examples
[INFO] dl4j-spark
[INFO] datavec-examples
[INFO] DeepLearning4j CUDA special examples
[INFO] nd4j-examples
[INFO] Reinforcement Learning4j Examples
[INFO] lstm-hdfs
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building DeepLearning4j Examples Parent 1.0.0-alpha
[INFO] ------------------------------------------------------------------------
Downloading from central: https://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-enforcer-plugin/1.0.1/maven-enforcer-plugin-1.0.1.pom
[INFO] ------------------------------------------------------------------------
[INFO] Reactor Summary:
[INFO]
[INFO] DeepLearning4j Examples Parent ..................... FAILURE [ 1.359 s]
[INFO] DeepLearning4j Examples ............................ SKIPPED
[INFO] dl4j-spark-examples ................................ SKIPPED
[INFO] dl4j-spark ......................................... SKIPPED
[INFO] datavec-examples ................................... SKIPPED
[INFO] DeepLearning4j CUDA special examples ............... SKIPPED
[INFO] nd4j-examples ...................................... SKIPPED
[INFO] Reinforcement Learning4j Examples .................. SKIPPED
[INFO] lstm-hdfs .......................................... SKIPPED
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 1.774 s
[INFO] Finished at: 2018-05-01T21:23:04+02:00
[INFO] Final Memory: 8M/34M
[INFO] ------------------------------------------------------------------------
[ERROR] Plugin org.apache.maven.plugins:maven-enforcer-plugin:1.0.1 or one of its dependencies could not be resolved: Failed to read artifact descriptor for org.apache.maven.plugins:maven-enforcer-plugin:jar:1.0.1: Could not transfer artifact org.apache.maven.plugins:maven-enforcer-plugin:pom:1.0.1 from/to central (https://repo.maven.apache.org/maven2): java.lang.RuntimeException: Unexpected error: java.security.InvalidAlgorithmParameterException: the trustAnchors parameter must be non-empty -> [Help 1]
[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 full debug logging.
[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/PluginResolutionException
Here is the pom.xml
http://maven.apache.org/xsd/maven-4.0.0.xsd">
<groupId>org.deeplearning4j</groupId>
<artifactId>deeplearning4j-examples-parent</artifactId>
<version>1.0.0-alpha</version>
<modelVersion>4.0.0</modelVersion>
<packaging>pom</packaging>
<name>DeepLearning4j Examples Parent</name>
<description>Examples of training different data sets</description>
<properties>
<!-- Change the nd4j.backend property to nd4j-cuda-8.0-platform, nd4j-cuda-9.0-platform or nd4j-cuda-9.1-platform to use CUDA GPUs -->
<nd4j.backend>nd4j-native-platform</nd4j.backend>
<!--<nd4j.backend>nd4j-cuda-9.1-platform</nd4j.backend>-->
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<shadedClassifier>bin</shadedClassifier>
<java.version>1.8</java.version>
<nd4j.version>1.0.0-alpha</nd4j.version>
<dl4j.version>1.0.0-alpha</dl4j.version>
<datavec.version>1.0.0-alpha</datavec.version>
<arbiter.version>1.0.0-alpha</arbiter.version>
<rl4j.version>1.0.0-alpha</rl4j.version>
<!-- For Spark examples: change the _1 to _2 to switch between Spark 1 and Spark 2 -->
<dl4j.spark.version>1.0.0-alpha_spark_1</dl4j.spark.version>
<datavec.spark.version>1.0.0-alpha_spark_1</datavec.spark.version>
<!-- Scala binary version: DL4J's Spark and UI functionality are released with both Scala 2.10 and 2.11 support -->
<scala.binary.version>2.11</scala.binary.version>
<hadoop.version>2.2.0</hadoop.version> <!-- Hadoop version used by Spark 1.6.3 and 2.2.1 (and likely others) -->
<guava.version>19.0</guava.version>
<logback.version>1.1.7</logback.version>
<jfreechart.version>1.0.13</jfreechart.version>
<jcommon.version>1.0.23</jcommon.version>
<maven-compiler-plugin.version>3.6.1</maven-compiler-plugin.version>
<maven-shade-plugin.version>2.4.3</maven-shade-plugin.version>
<exec-maven-plugin.version>1.4.0</exec-maven-plugin.version>
<maven.minimum.version>3.3.1</maven.minimum.version>
<javafx.version>2.2.3</javafx.version>
<javafx.runtime.lib.jar>${env.JAVAFX_HOME}/jfxrt.jar</javafx.runtime.lib.jar>
<aws.sdk.version>1.11.109</aws.sdk.version>
<jackson.version>2.6.6</jackson.version>
<scala.plugin.version>3.2.2</scala.plugin.version>
</properties>
<modules>
<module>dl4j-examples</module>
<module>dl4j-spark-examples</module>
<module>datavec-examples</module>
<module>dl4j-cuda-specific-examples</module>
<module>nd4j-examples</module>
<module>rl4j-examples</module>
<module>lstm-hdfs</module>
</modules>
<!-- Maven Enforcer: Ensures user has an up to date version of Maven before building -->
<build>
<plugins>
<plugin>
<artifactId>maven-enforcer-plugin</artifactId>
<version>1.0.1</version>
<executions>
<execution>
<id>enforce-default</id>
<goals>
<goal>enforce</goal>
</goals>
<configuration>
<rules>
<requireMavenVersion>
<version>[${maven.minimum.version},)</version>
<message>********** Minimum Maven Version is ${maven.minimum.version}. Please upgrade Maven before continuing (run "mvn --version" to check). **********</message>
</requireMavenVersion>
</rules>
</configuration>
</execution>
</executions>
</plugin>
<!-- Automated Code Formatting -->
<plugin>
<groupId>net.revelc.code.formatter</groupId>
<artifactId>formatter-maven-plugin</artifactId>
<version>2.0.0</version>
<configuration>
<configFile>${session.executionRootDirectory}/contrib/formatter.xml</configFile>
<directories>
<directory>dl4j-examples</directory>
<directory>dl4j-spark-examples</directory>
<directory>datavec-examples</directory>
<directory>dl4j-cuda-specific-examples</directory>
<directory>nd4j-examples</directory>
<directory>rl4j-examples</directory>
<directory>arbiter-examples</directory>
<directory>lstm-hdfs</directory>
</directories>
</configuration>
</plugin>
<plugin>
<groupId>com.lewisd</groupId>
<artifactId>lint-maven-plugin</artifactId>
<version>0.0.11</version>
<configuration>
<failOnViolation>true</failOnViolation>
<onlyRunRules>
<rule>DuplicateDep</rule>
<rule>RedundantPluginVersion</rule>
<rule>VersionProp</rule>
<rule>DotVersionProperty</rule>
</onlyRunRules>
</configuration>
<executions>
<execution>
<id>pom-lint</id>
<phase>validate</phase>
<goals>
<goal>check</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
<pluginManagement>
<plugins>
<plugin>
<groupId>org.eclipse.m2e</groupId>
<artifactId>lifecycle-mapping</artifactId>
<version>1.0.0</version>
<configuration>
<lifecycleMappingMetadata>
<pluginExecutions>
<pluginExecution>
<pluginExecutionFilter>
<groupId>com.lewisd</groupId>
<artifactId>lint-maven-plugin</artifactId>
<versionRange>[0.0.11,)</versionRange>
<goals>
<goal>check</goal>
</goals>
</pluginExecutionFilter>
<action>
<ignore/>
</action>
</pluginExecution>
</pluginExecutions>
</lifecycleMappingMetadata>
</configuration>
</plugin>
</plugins>
</pluginManagement>
</build>
<profiles>
<profile>
<id>OpenJFX</id>
<activation>
<jdk>1.7</jdk>
</activation>
<build>
<plugins>
<plugin>
<artifactId>maven-enforcer-plugin</artifactId>
<version>1.0.1</version>
<executions>
<execution>
<id>enforce-default</id>
<goals>
<goal>enforce</goal>
</goals>
<configuration>
<rules>
<requireProperty>
<property>env.JAVAFX_HOME</property>
<message>You must set the environment variable JAVAFX_HOME to the installation directory of the JavaFX 2.0 SDK! (with Oracle JDK1.7, $JRE_HOME/lib/jfxrt.jar)</message>
</requireProperty>
</rules>
</configuration>
</execution>
</executions>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-install-plugin</artifactId>
<version>2.5.2</version>
<executions>
<execution>
<id>install-external</id>
<phase>clean</phase>
<configuration>
<file>${javafx.runtime.lib.jar}</file>
<repositoryLayout>default</repositoryLayout>
<groupId>com.oracle</groupId>
<artifactId>javafx</artifactId>
<version>${javafx.version}</version>
<packaging>jar</packaging>
<generatePom>true</generatePom>
</configuration>
<goals>
<goal>install-file</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</build>
</profile>
</profiles>