git clone https://github.com/omegat-org/omegat.git
cd omegat
./gradlew clean installDist
A newly build OmegaT will be located in ./build/install/OmegaT
. That includes crossplatform OmegaT.jar + all the needed libs + docs.
Furthermore, command gradlew tasks
would show all that gradle is configured to do in OmegaT source.