I'm following the tutorial to build up a custom language and reached the end of part "4. Lexer and Parser Definition". All the code was generated as well and I marked "gen" folder as Generated Sources Root. IDEA do not complain and everything seems work fine but when I try to execute "runIde" script on Gradle but it raises some erros related to "gen" folder, the script cannot find the path by itself. I've also tried to build the plugin on (buildPlugin) and got same errors. What is going on and how can I fix that?