Get flake inputs from substituter

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1

Hi,

‘nix build’ seems to always download the flake inputs from GitHub rather than the substituter (but I might be missing something).
I expected that the narHash in the lock file would allow to download from the substituter.
Is it possible, or should I rather mirror nixpkgs to avoid downloading from GitHub in this case?

2

I indeed can observe the inputs being substituted. At least those that can be substituted.

I do not expect any input to be substitutable though, except for nixpkgs itself.

3

Hmmm I was using nix 2.8 but that’s probably too old, seems to work as expected with 2.16!