ci: run doc test in parallel

.cargo/config.toml

@@ -6,4 +6,4 @@ ci-min-test = "hack check --workspace --no-default-features --tests --examples"
 ci-default = "check --workspace --bins --tests --examples"
 ci-full = "check --workspace --all-features --bins --tests --examples"
 ci-test = "test --workspace --all-features --lib --tests --no-fail-fast -- --nocapture"
-ci-doctest = "hack test --workspace --all-features --doc --no-fail-fast -- --nocapture"
+ci-doctest = "test --workspace --all-features --doc --no-fail-fast -- --nocapture"

.github/workflows/ci.yml

@@ -80,13 +80,6 @@ jobs:
           command: ci-test
           args: --skip=test_reading_deflate_encoding_large_random_rustls
 
-      - name: doc tests
-        # due to unknown issue with running doc tests on macOS
-        if: matrix.target.os == 'ubuntu-latest'
-        uses: actions-rs/cargo@v1
-        timeout-minutes: 40
-        with: { command: ci-doctest }
-
       - name: Generate coverage file
         if: >
           matrix.target.os == 'ubuntu-latest'
@@ -106,5 +99,36 @@ jobs:
 
       - name: Clear the cargo caches
         run: |
-          cargo install cargo-cache --version 0.6.2 --no-default-features --features ci-autoclean
+          cargo install cargo-cache --version 0.6.3 --no-default-features --features ci-autoclean
           cargo-cache
+
+  rustdoc:
+    name: rustdoc
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Install Rust (nightly)
+        uses: actions-rs/toolchain@v1
+        with:
+          toolchain: nightly-x86_64-unknown-linux-gnu
+          profile: minimal
+          override: true
+
+      - name: Generate Cargo.lock
+        uses: actions-rs/cargo@v1
+        with: { command: generate-lockfile }
+      - name: Cache Dependencies
+        uses: Swatinem/rust-cache@v1.3.0
+
+      - name: Install cargo-hack
+        uses: actions-rs/cargo@v1
+        with:
+          command: install
+          args: cargo-hack
+
+      - name: doc tests
+        uses: actions-rs/cargo@v1
+        timeout-minutes: 40
+        with: { command: ci-doctest }