Icon tarballs generated by appstream-generator do not contain an architecture-specific suffix, which suggests that they include icons for all the architectures. However, when trying to get the generator working for a distro, I realized that the log lines:

INFO: Creating icon tarball.
INFO: Icon tarball(s) built.

only appear once per suite while exporting data for the first architecture that gets process.

Looking at the code, cached icon tarballs are only generated for the first architecture that calls exportData because both in processSuiteSection and in publishMetadataForSuiteSection, the boolean that controls the icon tarball generator is swapped after the first pass. If my understanding of the code in exportData is correct, that will generate an icon tarball using only the icons in packages present in the said architecture. If other architectures have additional packages with icons, those will get missing. Is there a specific reason for this behavior? Am I missing something and what I described is not what the code is doing (first time looking at D, so I apologize if this is the case)?