GWT (http://www.gwtproject.org/) is a toolkit for generating JavaScript applications from Java. RStudio is implemented with GWT, so we should package it if we ever want to offer an RStudio package for Guix.
The GWT repository is here: https://github.com/gwtproject/gwt This looks easy to build with ant-build-system, but only because all the bundled dependencies are in a separate repository: https://github.com/gwtproject/tools The “lib” directory contains a large number of Jars that are expected to be available when building GWT. It is not clear if all of these libraries are needed to compile GWT. Let’s not think about this now and just package as many of them as possible, leaving the difficult ones for later. The bad news is that there are 352 jars. The good news is that we already have a few of these packages and that there are a few duplicates providing different versions of the same tools. One of the dependencies is the Google Closure Compiler (for com.google.javascript.jscomp); progress on packaging it is tracked in issue #45554. -- Ricardo