ci: Run cargo-semver-checks

This should eventually be able to replace the `.txt` files.

Author: tgross35

.github/workflows/ci.yaml

@@ -67,10 +67,14 @@ jobs:
         run: |
           set -eux
           [ "${{ matrix.toolchain }}" = "1.63.0" ] && echo 'RUSTFLAGS=' >> "$GITHUB_ENV" || true
-          
+
       - name: Setup Rust toolchain
         run: ./ci/install-rust.sh
 
+      - name: Install semver-checks
+        uses: taiki-e/install-action@cargo-semver-checks
+        if: matrix.toolchain == 'stable'
+
       # FIXME(ci): These `du` statements are temporary for debugging cache
       - name: Target size before restoring cache
         run: du -sh target | sort -k 2 || true

ci/verify-build.sh

@@ -11,6 +11,7 @@ set -eux
 
 rust="$TOOLCHAIN"
 filter="${FILTER:-}"
+host_target=$(rustc -vV | awk '/^host/ { print $2 }')
 
 case "$(uname -s)" in
     Linux*)     os=linux ;;
@@ -25,6 +26,7 @@ esac
 echo "Testing Rust $rust on $os"
 
 if [ "$TOOLCHAIN" = "nightly" ] ; then
+    # For build-std
     rustup component add rust-src
 fi
 
@@ -108,6 +110,13 @@ test_target() {
             $cmd --no-default-features
         done
     fi
+
+    # FIXME(semver): can't pass `--target` to `cargo-semver-checks`
+    if [ "$rust" = "stable" ] && [ "$target" = "$host_target" ]; then
+        # Run semver checks on the stable channel
+        cargo semver-checks --only-explicit-features \
+            --features std,extra_traits
+    fi
 }
 
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