"No releases available for 's' on channel 'c' for architecture 'a'" when promoting a snap

% snapcraft promote --from-channel edge/hwacc --to-channel stable/hwacc chromium
snapcraft promote does not have a stable CLI interface. Use with caution in scripts.
No releases available for 'chromium' on channel 'latest/edge/hwacc' for architecture 'i386'.
Ensure the selected channel contains released revisions for this architecture.

Why does it even matter if edge/hwacc has a i386 build to promote? I only need (and build) the amd64 snap.

How to work around that issue?