Comment 4 for bug 784112

OK, the problem here is that my main archive is the internal arm one:
deb http://arm-archive-ubuntu.cambridge.arm.com/ubuntu/ maverick main restricted universe
deb-src http://arm-archive-ubuntu.cambridge.arm.com/ubuntu/ maverick main restricted universe

So once the installer has sanitized your repo set to remove 3rd-party ones there is nothing left so it goes 'help, it's all broken!'.

It would be nice if it gave a more helpful error message at least like 'you have no main repositories left after I sanitised things' rather than trying to tell you a package you _do_ have is not present. Even better would be to be a bit more liberal/smart and say 'is this a mirror of the ubuntu archive?'