Major Description
Running buildr under jruby is slow. A large portion of the blame can be attributed to rubygems and some can be attributed to the startup time of parsing the ruby files and the bytecode compilation under the JVM.
It seems this is largely fixable by applying a few ugly hacks. These include;
- Extracting all the ruby code into one directory. (Seems to show the biggest improvement)
- Running jrubyc over the codebase and replacing all the .rb files with quires against the .class files such as warbler does
In one project we applied these techniques and our startup time when from ~23s to ~1.5s however some projects see even better improvements. See [1] for a better explanation and some additional tricks to try.