Why caching is not working with Rust/devenv

Build Environment Caching Dependencies
1

I setup a CI pipeline:

version: 2.1

commands:
  restore_cache_cmd:
    steps:
      - restore_cache:
          key: cache_cmd-v1-{{ arch }}-{{ checksum "Cargo.lock" }}

  save_cache_cmd:
    steps:
      - save_cache:
          key: cache_cmd-v1-{{ arch }}-{{ checksum "Cargo.lock" }}
          paths:
            - "~/.cargo"
            - "./target"

jobs:
  # Precompile all the rust dependencies
  compile:
# Has all the build tools installed, clean env otherwise
    executor: nix-executor
    steps:
      - restore_cache_cmd
      - run:
          name: Compile App
          command: |
            cargo test --all --no-run
            cargo zigbuild --target x86_64-unknown-linux-musl --bin server --release
      - save_cache_cmd

I expect that if I run this step first as root for the rest it will save time, but I still get a lot of time compiling after it. I see in the logs the cache is restored.

Testing in my machine works (insofar i don’t have the same env as CI).