Add clippy for a no_std target.

Signed-off-by: Daira-Emma Hopwood <[email protected]>

Author: daira

.github/workflows/lints-stable.yml

@@ -16,3 +16,49 @@ jobs:
           token: ${{ secrets.GITHUB_TOKEN }}
           working-directory: ${{ inputs.target }}
           deny: warnings
+
+  clippy-nostd:
+    name: Clippy (MSRV) no_std for ${{ matrix.target }}
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        target:
+          - wasm32-wasi
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          path: crate_root
+      # We use a synthetic crate to ensure no dev-dependencies are enabled, which can
+      # be incompatible with some of these targets.
+      - name: Create synthetic crate for testing
+        run: cargo init --edition 2021 --lib ci-build
+      - name: Copy Rust version into synthetic crate
+        run: cp crate_root/rust-toolchain.toml ci-build/
+      - name: Copy patch directives into synthetic crate
+        run: |
+          echo "[patch.crates-io]" >> ./ci-build/Cargo.toml
+          cat ./crate_root/Cargo.toml | sed "0,/.\+\(patch.crates.\+\)/d" >> ./ci-build/Cargo.toml
+      - name: Add no_std pragma to lib.rs
+        run: |
+          echo "#![no_std]" > ./ci-build/src/lib.rs
+      - name: Add dependencies of the synthetic crate (e.g. sapling-crypto)
+        working-directory: ./ci-build
+        run: cargo add --no-default-features --features circuit --path ../crate_root
+      - name: Add orchard with the circuit feature
+        working-directory: ./ci-build
+        run: cargo add orchard --no-default-features --features "circuit" --path ../crate_root
+      - name: Add lazy_static with the spin_no_std feature
+        working-directory: ./ci-build
+        run: cargo add lazy_static --features "spin_no_std"
+      - name: Add typenum with the no_std feature
+        working-directory: ./ci-build
+        run: cargo add typenum --features "no_std"
+      - name: Show Cargo.toml for the synthetic crate
+        working-directory: ./ci-build
+        run: cat Cargo.toml
+      - name: Add target
+        working-directory: ./ci-build
+        run: rustup target add ${{ matrix.target }}
+      - name: Clippy no_std for target
+        working-directory: ./ci-build
+        run: cargo clippy --verbose --target ${{ matrix.target }}