I386 packages in launchpad ppa's

Does anyone have a simple explanation of what triggers i386 builds or prevents i386 builds in launchpad ppa’s?
So far can’t find any rhyme or reason myself…

What’s the actual issue you’re trying to debug?

This documentation is probably what you’re looking for? The architecture: all or architecture: any?

This issue is this -
Starting in late Nov. or so, sources that always built both i386 and amd64 packages in ppa’s started to only build amd64 packages.
Some sources still do build both archs, many don’t.
It doesn’t appear to be an issue of the control file, the very same builds will do both archs in prior to 20.04 builds.
Sources that do build both have basically the same control file in regards to arch, typically Architecture: any

At first glance when this started it appeared that sources that build binaries get amd64 only, sources that build libs get both.
after a bit that is clearly not the case.

Ex. ppa’s
my personal
https://launchpad.net/~mc3man/+archive/ubuntu/focal6/+packages
smplayer ppa ( note his prior focal build from early nov had both arch’s
https://launchpad.net/~rvm/+archive/ubuntu/smplayer/+packages?field.name_filter=&field.status_filter=published&field.series_filter=focal
The unity 7 ppa (all packages there now have newer repo builds for both arch’s.
https://launchpad.net/~unity7maintainers/+archive/ubuntu/unity7-desktop/+packages?field.name_filter=&field.status_filter=published&field.series_filter=focal
firefox daily
https://launchpad.net/~ubuntu-mozilla-daily/+archive/ubuntu/ppa/+packages?field.name_filter=&field.status_filter=published&field.series_filter=focal

ect. ect.
So looking for what determines doing i386 builds?
( by default all ppa’s are set to do amd64 & i386 builds…

This is normal. Focal only partially supports i386 (see the Discourse thread about it), and Launchpad only creates i386 PPA builds for packages that have i386 support in Ubuntu itself. There isn’t currently a way for a PPA owner to override this.

Ok, unfortunate…
what I’d want to avoid is creating a situation where a ppa updated lib causes some user a breakage due to an i386 package of same version not being available.
Haven’t uncovered that yet though wouldn’t doubt it could occur, maybe with wine or steam…?