fix

.github/workflows/ci.yml

@@ -45,7 +45,7 @@ jobs:
       run: |
         rustup default nightly
         rustup component add rustfmt
-        cargo install mdbook
+        test -x $HOME/.cargo/bin/mdbook || ./ci/install-mdbook.sh
         rustc --version
     - name: mdbook
       run: |

.github/workflows/clippy.yml

@@ -11,7 +11,7 @@ jobs:
           component: clippy
       - uses: actions-rs/toolchain@v1
         with:
-            toolchain: nightly
+            toolchain: ${{ steps.component.outputs.toolchain }}
             override: true
       - run: rustup component add clippy
       - uses: actions-rs/clippy-check@v1