Per #638517, we would like to add a `Commands` field to the `.deb`'s
control file to support the "command-not-found" feature.

Ideally, `dpkg-gencontrol` would allow substitution variables in it.
Optimally, `dpkg-gencontrol` would also optimize the field similar to
what it does with `Depends` in case values are repeated (`Commands` can
use a simpler merging since it is only basenames and not full blown
dependency clause).

But for starters, just having `dpkg-gencontrol` not warn about the field
and replacing substvars would be a great start for post-trixie.

Best regards,
Niels

Niels Thykier:

Added content, the warning comes because I used a `Commands` in the
source control (`debian/control`; well, technically an auto-generated
variant of it due to dbgsym support, etc. ).

When I use `XB-Commands` it works without a warning and substitution
works correctly. So I think it is just a matter of `dpkg-dev` updating
its list of known fields for binary controls.

Best regards,
Niels