Set default architecture (without passing --platform)?

[flouthoc]

Discussed in #25623

^{Originally posted by jeliker1 March 18, 2025}
I have been happily using podman to create fnproject.io deployments until this week. The issue is that the build is for arm64 (which is my local machine Mac M4) though previously I was building amd64 without doing anything special.

Frankly can't tell what changed except possibly a version upgrade for podman. Is all very perplexing as I don't find any reference to this behavior changing (even if it is version related).

Any recommendations how to set a default build architecture such as you would set with --platform since the fn executable doesn't support passing through parameters like that. It can pass build-args but I've not found anything that will set the build target architecture. Thank you for any advice.

Jon-Eric