Comment 2 for bug 919216

Well, in the case of failing dependencies, it seems like any choice at the prompt gives a 0 return value. Is the rationale that 'aptitude managed to abort successfully' equals success? If that is the intended functionality, then I cannot trust aptitude to give any meaningful return value.

And as far as I can see, the bug you refer to only concerns failing to install a specified version. At least that's what it patches.