Streamline 'local build' instructions

[rkratky]

The Build packages locally article should suggest one way of building packages. An authoritative recommendation. The other methods can be mentioned, but the article shouldn't put them all side by side.

[Hyask]

As discussed elsewhere, I'll post here the commands I use, in the hope to spark a discussion :-)

I've no idea what the standard way should be, with the tools we have (and their weird default behaviors).
For example, I mostly end up with the following two commands, but they hardly feel "standard" to me:

• for binary packages: sbuild --no-clean-source -d resolute-proposed
sbuild is configured with unshare by default with the following in my .config/sbuild/config.pl:

  $chroot_mode = "unshare";
  $unshare_mmdebstrap_keep_tarball = 1;
  $external_commands = { "build-failed-commands" => [ [ '%SBUILD_SHELL' ] ] };

  --no-clean-source is to skip checking for build deps on the host, given that it will build in an unshare environment. There should be a more fined-grained option here, I believe.
• for source packages:

  dpkg-buildpackage \
  --build=source \
  --no-pre-clean \
  --no-check-builddeps \
  -sa $(git ubuntu prepare-upload args)
  

  The --no-pre-clean option is because I always work in a git repo, so it's easy to see if it's clean, and it avoids failing on some clean steps that sometimes require some build deps (I believe, I've had that option since forever, so don't have much recent experience without).

My two bronze coins 🪙 🪙

[rkratky]

Related: #295