I'm seeing the errors below when running the command to generate coverage reporting:

mvn antrun:run@ts.jacoco.report-ant -Dcoverage -Dtarget=report -Djboss.dist=dist/target/wildfly-29.0.0.Final-SNAPSHOT

open target/coverage-report/html/index.html

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-antrun-plugin:1.8:run (ts.jacoco.report-ant) on project wildfly-parent: An Ant BuildException has occured: Error while creating report

[ERROR] around Ant part ...<report>... @ 7:11 in /Users/cfang/dev/target/antrun/build-main.xml: Error while analyzing system/layers/base/org/yaml/snakeyaml/main/snakeyaml-2.0.jar@org/yaml/snakeyaml/internal/Logger$Level.class. Can't add different class with same name: org/yaml/snakeyaml/internal/Logger$Level

Also it will be good to upgrade to jacoco 0.8.10 (the latest version as of now).