add rustup install since it is not in this image

Author: graydon

.github/workflows/build.yml

@@ -82,7 +82,10 @@ jobs:
         uses: namespacelabs/nscloud-cache-action@v1
         with:
           path: ${{ env.CACHED_PATHS }}
-      
+
+      - name: install rustup
+        run: ./install-rust.sh
+
       - name: install rustup components
         run: rustup component add rustfmt
 

install-rust.sh

@@ -7,6 +7,8 @@
 # is version-controlled and run in CI to make the dependency explicit (and to
 # use a version newer than the debian packages).
 
+rustup --version >/dev/null 2>&1 && exit 0
+
 # Fail on any error
 set -e