I agree. Among all the open-source projects I've built, the OpenJDK is one of the easiest and most straight-forward I've encountered — even when cross-compiling

I agree. Among all the open-source projects I've built, the OpenJDK is one of the easiest and most straight-forward I've encountered — even when cross-compiling for 32-bit ARM. They did a great job rewriting the build system a few years back.