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javakotlingradlegwtlibgdx

LibGDX GWT/HTML with Kotlin: "No source code is available for type <XYZ>, did you forget to inherit a required module?"

I generated a simple libGDX project with no dependencies. When I tried to build it as HTML app with Gradle (./gradlew html:dist), I get the following error message:

Tracing compile failure path for type 'xjcl.downgradius.client.HtmlLauncher'
   [ERROR] Errors in 'file:/home/jan/Dropbox/py/AndroidStudioProjects/Downgradius_Android/html/src/xjcl/downgradius/client/HtmlLauncher.java'
      [ERROR] Line 49: No source code is available for type xjcl.downgradius.DowngradiusGame; did you forget to inherit a required module?

I think the problem is caused by me using Kotlin in this project, and libGDX being intended for Java development. I observed that when I made a new main Game class in Java, that class was found by GWT, but not the Kotlin classes it imports.

I know Kotlin does some re-packaging (for example, if you put funA and funB in file Foo, they will be re-packaged as part of a new FooKt package, I think), but it should be able to find it as

  • it is declared in the right package (xjcl.downgradius)
  • it is declared as the only class in its file
  • I get no IDE warnings about importing it from Java.

I also tried converting Kotlin to Java code but the resulting Java code was full of errors.

Solution

  • Your assumptions are correct. GWT compiler works on Java sources. The error message it gives you is correct: There are no Java source code files to be found, you say it yourself that you used Kotlin.

    If you want to use GWT, convert to correct Java source code.