Hm, that’s quite strange, I don’t understand why it wouldn’t just create the directories it needs. When you install Julia by just copying the binaries, it just generates all these directories for you, I don’t understand why it would not do that from the arch image.
Out of curiosity, when you type ], what does the prompt say? For example, you should see
(v1.0) pkg>
Another thing you can try is doing ]activate . from some directory, it’s possible that once you do that it will generate a Project.toml and a Manifest.toml in that directory.