The SonarScanner for Gradle 3.0 documentation mentions in the defaults:
sonar.sources
:${sourceSets.main.allSource.srcDirs}
(filtered to only include existing directories)
This is incorrect, looking at the source it is clear is uses sourceSets.main.allJava.srcDirs
.
This is unfortunate and leads to warnings with Sonarqube 8.5, as src/main/resources
is not included by default, missing Thymeleaf templates.