Good day,

Recently, I have stumbled upon the possibility of recompiling the entire os using the "apt-build world" command, however I am having some difficulties getting it to work.

As a simple example, if I do (as root):
apt-build install leafpad
I see the sources download and compile, however before the resulting package actually installs, I am left with this error:
E: The value 'apt-build' is invalid for APT::Default-Release as such a release is not available in the sources
I am running a barebones install of Ubuntu Oneiric Server edition (freshly installed) on an Asus T91MT netbook.

The reason I am experimenting with apt-build world is due to the significant speed increase I achieved after tweaking and recompiling the kernel for the Atom processor.
I want to optimize the entire OS in the same way. On top of this, I am interested in the learning experience, and would like to write a guide on how to accomplish this task once I get it working.

I am well aware that Ubuntu is not suited for building from source, and that Gentoo or LFS would be better choices, however I am quite a fan of Ubuntu and don't see any reason why it shouldn't be possible.

Thank you for any tips / help!