<dependency>
  <groupId>org.apache.geronimo.arthur.knights</groupId>
  <artifactId>slf4j-knight</artifactId>
  <version>${arthur.version}</version>
</dependency>Arthur Slf4j knight is responsible to force some SLF4j and SLF4J-JUL class initialization at build time.
<dependency>
  <groupId>org.apache.geronimo.arthur.knights</groupId>
  <artifactId>slf4j-knight</artifactId>
  <version>${arthur.version}</version>
</dependency>The slf4j-knight handles some build time initialization to make slf4j-jdk14 working with graalvm compilation.
You must register the slf4j knight in arthur-maven-plugin:
<plugin>
  <groupId>org.apache.geronimo.arthur</groupId>
  <artifactId>arthur-maven-plugin</artifactId>
  <version>${arthur.version}</version>
  <configuration>
    <main>org.company.Main</main>
    <graalExtensions>
      <graalExtension>slf4j</graalExtension>
    </graalExtensions>
  </configuration>
</plugin>Previous: Knights