Turns out that this is an “assumption” problem and not a bug.
I assumed that the default behaviour would be to set up sources.Turns out that the default behaviour of the installer is to *not* set up the sources, but only set up the installation media as a source.
Having the option for that seems sane, but shouldn't setting up network sources be the default selection? It seems to me that 99% of the time, people will want apt to be able to get packages from outside the installation media.
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