Add rust-src to nightly build

Author: jonathanpallant

.github/workflows/build.yml

@@ -65,6 +65,7 @@ jobs:
         run: |
           rustup install nightly
           rustup default nightly
+          rustup component add rust-src --toolchain nightly
       - name: Build
         run: |
           cargo build --target ${{ matrix.target }} -Zbuild-std=core
@@ -215,7 +216,9 @@ jobs:
     runs-on: ubuntu-latest
     needs: [build-all]
     steps:
-      - run: sudo apt-get -y update && sudo apt-get -y install qemu
+      - run: sudo apt-get -y update && sudo apt-get -y install qemu-system-arm
+      - name: Checkout
+        uses: actions/checkout@v4
       - run: ./tests.sh
 
   # Gather all the above xxx-all jobs together for the purposes of getting an overall pass-fail