Currently, build/archives/BUILD.gn in the engine includes many rules for building zip archives that appear to be used to generate archives for upload to cloud storage, which the tool then later pulls down. For example :archive_gen_snapshot generates a zip file containing gen_snapshot_${target_arch}.

However, the archives used by the tool are produced by the rules in ci/builders/mac_host_engine.json recipe file in the engine, which assemble the zip files from multiple builds. Interestingly, one of the targets relied on during the builds from which the archives are assembled is the flutter/build/archives:archive_gen_snapshot rule, presumably because it generates the correct gen_snapshot binaries prior to producing gen_snapshot.zip (which presumably is then ignored).

We should eliminate the archive targets from build/archives/BUILD.gn and instead update the build targets to point at the underlying deps that actually generate the binaries that we later archive. At a minimum, these targets should be annotated with comments to avoid future build archaeologists going down the same rabbit hole that @christopherfujino and I just did.