This inspection reports when a class / interface that contains @Mapping or @ValueMapping annotations is not annotated with @Mapper or @MapperConfig.
Classes not annotated with @Mapper will not be picked up by the MapStruct annotation processor, and class not annotated with @MapperConfig will not be used as configuration.

//wrong
public interface EmployeeMapper {
    @Mapping(source = "employeeName", target = "name")
    Employee toEmployee(EmployeeDto employeeDto, @Context CycleAvoidingMappingContext context);
}

//correct
@Mapper
public interface EmployeeMapper {
    @Mapping(source = "employeeName", target = "name")
    Employee toEmployee(EmployeeDto employeeDto, @Context CycleAvoidingMappingContext context);
}