message: chore: use rust-toolchain to override toolchain
diff: @@ -17,7 +17,9 @@ jobs:
  - uses: actions-rs/toolchain@v1
  with:
  toolchain: nightly
  - override: true
  + - name: overwrite toolchain
  + # It's easier to clean than `rustup override`
  + run: echo nightly > rust-toolchain
  - name: unit coverage
  run: make cov
  - name: integration cov
  