In order to be able to use JTransc you first need install Haxe and make sure that haxe and haxelib binaries are available in path. You can grab the right version from here:
JTransc is meant to be used with Haxe >= 3.3, though it could work on 3.2 too. https://haxe.org/download/version/3.3.0-rc.1/
Usually installers, put haxe and haxelib binaries on path. But in the case you are using non-installer versions, you have to put folder containing those programs in your path. Also You will have to execute haxelib setup to setup haxelib path.
You first have to install Haxe, and in order to use gdx-backend-jtransc you have to install lime and setup the targets you are going to use.
In order to install lime. You have to execute the following command: haxelib setup lime.
Commands required to generate language-specific binaries:
haxelib install hxcpphaxelib install hxcshaxelib install hxjavaUpdate. After this issue is done https://github.com/jtransc/jtransc/issues/43, haxe is installed automatically at $HOME/.jtransc/haxe/version/
Gradle plugin provides two tasks per target: runXXX which runs application in debug mode (can be slow on C++), and distXXX which generates a release version of the application.
Debugging is still a work in progress. It will work with the intelliJ plugin.
You can see all the supported targets and how to setup them here.