&gt; to just copy all of Ubuntu&#x27;s (or Debian&#x27;s) binary packages and build a new derivative distribution on top of it<p>This is okay. However, copying Ubuntu’s <i>and</i> Debian’s packages into the same repository and then mixing them willy-nilly is not.<p>You can either:<p>a) Base your derivative on binaries from Debian xor Ubuntu, then add source packages compiled with these binaries as you like.<p>or<p>b) Base your derivative on sources from Debian and&#x2F;or Ubuntu, then compile everything together with your custom packages to make sure that all ABIs match.