Yeah, especially if add --weak SomePackage would not only add SomePackage = ... to weakdeps, but also SomePackageExt = SomePackage to [extensions] and SomePackageExt.jl to ext/ with the empty module skeleton.

So if I am not missed anything, currently I still have to edit Project.toml directly to add weak deps?

correct

Technically you can already add weak deps via --weak. That's new in 1.11. What cannot be done is automatically create an extension that depends on them, or add that weak dep to an existing extension.

Proposal here #4016

Technically you can already add weak deps via --weak. That's new in 1.11. What cannot be done is automatically create an extension that depends on them, or add that weak dep to an existing extension.

That's great! I just don't want to deal those UUID manually.