Merge pull request #43 from DeterminateSystems/graham/fh-272-detsys-t…

…s-create-a-helper-to-assert-nix-is-available-ahead

Preflight nix, or don't fail

.github/workflows/ci.yml

@@ -10,7 +10,7 @@ jobs:
     name: Build
     runs-on: ubuntu-22.04
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Install Nix
         uses: DeterminateSystems/nix-installer-action@main
       - uses: DeterminateSystems/magic-nix-cache-action@main
@@ -31,6 +31,19 @@ jobs:
       - run: git status --porcelain=v1
       - run: test $(git status --porcelain=v1 2>/dev/null | wc -l) -eq 0
 
+  test-no-nix:
+    name: "Test: Nix not installed"
+    runs-on: ubuntu-22.04
+    permissions:
+      id-token: "write"
+      contents: "read"
+    env:
+      ACTIONS_STEP_DEBUG: true
+    steps:
+      - uses: actions/checkout@v4
+      - name: Cache the store
+        uses: ./
+
   run-x86_64-linux:
     name: Run x86_64 Linux
     runs-on: ubuntu-22.04
@@ -40,7 +53,7 @@ jobs:
     env:
       ACTIONS_STEP_DEBUG: true
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Install Nix
         uses: DeterminateSystems/nix-installer-action@main
         with:
@@ -62,7 +75,7 @@ jobs:
     env:
       ACTIONS_STEP_DEBUG: true
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Install Nix
         uses: DeterminateSystems/nix-installer-action@main
         with:
@@ -85,7 +98,7 @@ jobs:
     env:
       ACTIONS_STEP_DEBUG: true
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Install Nix
         uses: DeterminateSystems/nix-installer-action@main
         with:

.github/workflows/flakehub-cache.yml

@@ -22,7 +22,7 @@ jobs:
           - nix-system: "x86_64-linux"
             runner: "ubuntu-22.04"
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: DeterminateSystems/nix-installer-action@main
       - uses: DeterminateSystems/magic-nix-cache-action@main
         with:

README.md

@@ -45,7 +45,7 @@ jobs:
       id-token: "write"
       contents: "read"
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: DeterminateSystems/nix-installer-action@main
       - uses: DeterminateSystems/magic-nix-cache-action@main
       - uses: DeterminateSystems/flake-checker-action@main