rockboxdev.sh is perfectly capable of compiling the toolchains.
However, it assumes that your environment is actually capable of compiling the toolchains (ie. meeting dependencies). For everything except the YP-R0 toolchain, these dependencies are very simply met (and documented).
From a clean install, only these packages should be needed:
build-essential libc6-dev libgmp3-dev libmpfr-dev texinfo
There are a few packages that will be used if present, but are not needed (bison, CLooG, flex, ...the list goes on).
My guess is that instead of looking at the error the toolchain compilation failed with (which will always be your clue as to why it failed), you've assumed it is broken and stopped there. It does work, though. If you are unable to work out why compilation is failing for you, posting the error from the output is infinitely more helpful that simple saying "It's buggy" (simplification taken from another post).
[Saint]