Cleaning output files: out/production/module/Base$A.class out/production/module/Base$B.class out/production/module/Base.class End of files Compiling files: src/Base.kt End of files Cleaning output files: out/production/module/META-INF/module.kotlin_module out/production/module/UseKt.class End of files Compiling files: src/use.kt End of files COMPILATION FAILED when expression must be exhaustive, add necessary 'is C' branch or 'else' branch instead Cleaning output files: out/production/module/Base$A.class out/production/module/Base$B.class out/production/module/Base$C.class out/production/module/Base.class End of files Compiling files: src/Base.kt src/use.kt End of files