try building nix explicitly

Author: catvw

.github/actions/checkout/action.yml

@@ -7,9 +7,7 @@ runs:
 
   steps:
     - uses: DeterminateSystems/nix-installer-action@v6
-
     - uses: DeterminateSystems/magic-nix-cache-action@v2
-
     - uses: HatsuneMiku3939/direnv-action@v1.0.2
       with:
         direnvVersion: 2.32.3

.github/workflows/mdbook-deploy.yml

@@ -20,8 +20,8 @@ jobs:
       - name: Checkout `carrie` (we hope)
         uses: ./.github/actions/checkout
 
-      - name: misc
-        run: ls /home/runner/.nix-profile/bin/
+      - name: actually build nix
+        run: nix build .
 
       - name: Build docs
         run: mdbook build