in src/main/java/org/apache/maven/plugins/jlink/JLinkExecutor.java [132:143]
public Optional<File> getJmodsFolder(/* nullable */ File sourceJdkModules) {
if (getToolchain().isPresent()) {
return super.getJmodsFolder(sourceJdkModules);
}
if (sourceJdkModules != null && sourceJdkModules.isDirectory()) {
return Optional.of(new File(sourceJdkModules, JMODS));
}
// ToolProvider does not need jmods folder to be set.
return Optional.empty();
}