Use the toolchain file in GitHub CI (stellar#195)

.github/workflows/rust.yml

@@ -22,8 +22,8 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v3
-    - run: rustup update stable && rustup default stable
-    - run: find . -type f -name '*.rs' -print0 | xargs -I {} -0 rustfmt --check "{}"
+    - run: rustup update
+    - run: cargo fmt --all --check
 
   build-and-test:
     strategy:
@@ -48,12 +48,8 @@ jobs:
     runs-on: ${{ matrix.sys.os }}
     steps:
     - uses: actions/checkout@v3
-    - uses: actions-rs/toolchain@16499b5e05bf2e26879000db0c1d13f7e13fa3af
-      with:
-        toolchain: stable
-        default: true
-        components: rustfmt, clippy
-        target: ${{ matrix.sys.target }}
+    - run: rustup update
+    - run: rustup target add ${{ matrix.sys.target }}
     - run: cargo install --locked --version 0.5.14 cargo-hack
     - run: cargo hack --feature-powerset check --profile ${{ matrix.profile }} --target ${{ matrix.sys.target }}
     - if: matrix.sys.test

Makefile

@@ -1,5 +1,7 @@
 all: build test
 
+export RUSTFLAGS=-Dwarnings
+
 test:
 	cargo hack --feature-powerset test
 
@@ -8,3 +10,9 @@ build:
 
 watch:
 	cargo watch --clear --watch-when-idle --shell '$(MAKE)'
+
+fmt:
+	cargo fmt --all
+
+clean:
+	cargo clean

rust-toolchain.toml

@@ -0,0 +1,4 @@
+[toolchain]
+channel = "stable"
+targets = ["wasm32-unknown-unknown"]
+components = ["rustc", "cargo", "rustfmt", "clippy", "rust-src"]