[goku12]

> It looks from the docs that uv may also support it?

I was just repeating what chatgpt told me - that uv does the same thing as npm. The documentation wasn't clear about exactly what it does either. So I had to confirm it using strace. You are indeed correct. UV does hardlink the dependencies from the global cache to the project venv. So that's good!

There's just one caveat. Hardlinking is not possible if the project and the cache are on different file systems. Even btrfs subvolume mounts from a single physical volume is considered as different filesystems. I think pnpm quite happily symlinks it instead of hardlinking it when such a situation arises (I'm not sure though. Need to check that as well.) UV doesn't do that. It complains (prints a warning) and just copies the entire thing over to the venv. So you won't get that advantage with uv if the venv and the cache are on different filesystems (like in my system). I don't know how many developers actually deal with this problem.