tvix-cli eval without shelling out to `nix-store --add`

gistfile1.txt

tvix-cli from https://cl.tvl.fyi/c/depot/+/8572/33:

❯ /nix/store/fi3j1sbpd2fzwbjnak924z58zhpd07j0-hyperfine-1.16.1/bin/hyperfine --warmup 10 './target/release/tvix -E "with import <nixpkgs>{}; toString stdenv"' 'nix-instantiate --eval --json --expr "with import <nixpkgs>{}; toString stdenv"'
Benchmark 1: ./target/release/tvix -E "with import <nixpkgs>{}; toString stdenv"
  Time (mean ± σ):      1.235 s ±  0.013 s    [User: 1.161 s, System: 0.074 s]
  Range (min … max):    1.218 s …  1.254 s    10 runs
 
Benchmark 2: nix-instantiate --eval --json --expr "with import <nixpkgs>{}; toString stdenv"
  Time (mean ± σ):     193.7 ms ±   3.4 ms    [User: 161.7 ms, System: 32.0 ms]
  Range (min … max):   190.3 ms … 203.1 ms    14 runs
 
Summary
  'nix-instantiate --eval --json --expr "with import <nixpkgs>{}; toString stdenv"' ran
    6.38 ± 0.13 times faster than './target/release/tvix -E "with import <nixpkgs>{}; toString stdenv"'



❯ /nix/store/fi3j1sbpd2fzwbjnak924z58zhpd07j0-hyperfine-1.16.1/bin/hyperfine --warmup 10 './target/release/tvix -E "with import <nixpkgs>{}; toString hello"' 'nix-instantiate --eval --json --expr "with import <nixpkgs>{}; toString hello"'
Benchmark 1: ./target/release/tvix -E "with import <nixpkgs>{}; toString hello"
  Time (mean ± σ):      1.346 s ±  0.020 s    [User: 1.264 s, System: 0.082 s]
  Range (min … max):    1.317 s …  1.383 s    10 runs
 
Benchmark 2: nix-instantiate --eval --json --expr "with import <nixpkgs>{}; toString hello"
  Time (mean ± σ):     212.2 ms ±   5.8 ms    [User: 173.4 ms, System: 31.9 ms]
  Range (min … max):   206.5 ms … 223.6 ms    13 runs
 
Summary
  'nix-instantiate --eval --json --expr "with import <nixpkgs>{}; toString hello"' ran
    6.35 ± 0.20 times faster than './target/release/tvix -E "with import <nixpkgs>{}; toString hello"'