I don't think podman can do this within a single run. It might be feasible
to do the setup (installing build-dependencies) with networking enabled;
leave the root filesystem of that container intact; and reuse it as the
root filesystem of the container in which the actual build runs, this time
with --network=none?
Or the "install build-dependencies" step (and other setup) could perhaps
even be represented as a `podman build` (with a Dockerfile/Containerfile,
FROM the image you had as your starting point), outputting a temporary
container image, in which the actual dpkg-buildpackage step can be invoked
by `podman run --network=none --rmi`?
Lot's of things to catch up on for me, but I remember writing an article a few years
ago related to this topic. I imagine that one could whip up some kind of wrapper
that is building a container either from a tarball created via mmboostrap or similar
using buildah, have it install all necessary build dependencies, and then use
podman to run the actual build:
I also briefly started playing with debcraft, which I really like from a usability
perspective. It clearly doesn't have all the bells and whistles that come with schroot,
but I do like the fact that I can very easily enter into a container with the build
results to play around and debug stuff.