Fix nix installer cache issue

.github/actions/bench/action.yml

@@ -41,11 +41,10 @@ inputs:
 runs:
   using: composite
   steps:
-    - name: Setup nix
-      if: ${{ inputs.nix-shell != '' }}
-      uses: ./.github/actions/setup-nix
+    - uses: ./.github/actions/setup-shell
       with:
-        devShell: ${{ inputs.nix-shell }}
+        nix-shell: ${{ inputs.nix-shell }}
+        custom_shell: ${{ inputs.custom_shell }}
         script: |
           ARCH=$(uname -m)
           cat >> $GITHUB_STEP_SUMMARY <<-EOF
@@ -59,14 +58,6 @@ runs:
             ## CPU Info
             $(cat /proc/cpuinfo)
           EOF
-    - name: Set shell
-      shell: bash
-      run: |
-        if [[ ${{ inputs.nix-shell }} != '' ]]; then
-          echo SHELL="nix develop .#${{ inputs.nix-shell }} -c bash -e {0}" >> $GITHUB_ENV
-        else
-          echo SHELL="${{ inputs.custom_shell }}" >> $GITHUB_ENV
-        fi
     - name: Run benchmark
       shell: ${{ env.SHELL }}
       run: |

.github/actions/cbmc/action.yml

@@ -17,11 +17,10 @@ runs:
   using: composite
   steps:
       - uses: actions/checkout@v4
-      - name: Setup nix
-        if: ${{ inputs.nix-shell != '' }}
-        uses: ./.github/actions/setup-nix
+      - uses: ./.github/actions/setup-shell
         with:
-          devShell: ${{ inputs.nix-shell }}
+          nix-shell: ${{ inputs.nix-shell }}
+          custom_shell: ${{ inputs.custom_shell }}
           script: |
             cat >> $GITHUB_STEP_SUMMARY << EOF
               ## Setup
@@ -33,14 +32,6 @@ runs:
               - $(${{ inputs.cross_prefix }}gcc --version | grep -m1 "")
               - $(bash --version | grep -m1 "")
             EOF
-      - name: Set shell
-        shell: bash
-        run: |
-          if [[ ${{ inputs.nix-shell }} != '' ]]; then
-            echo SHELL="nix develop .#${{ inputs.nix-shell }} -c bash -e {0}" >> $GITHUB_ENV
-          else
-            echo SHELL="${{ inputs.custom_shell }}" >> $GITHUB_ENV
-          fi
       - name: Run CBMC proofs
         shell: ${{ env.SHELL }}
         run: |

.github/actions/functest/action.yml

@@ -23,10 +23,10 @@ runs:
   using: composite
   steps:
       - name: Setup nix
-        uses: ./.github/actions/setup-nix
-        if: ${{ inputs.nix-shell != '' }}
+        uses: ./.github/actions/setup-shell
         with:
-          devShell: ${{ inputs.nix-shell }}
+          nix-shell: ${{ inputs.nix-shell }}
+          custom_shell: ${{ inputs.custom_shell }}
           script: |
             ARCH=$(uname -m)
             cat >> $GITHUB_STEP_SUMMARY <<-EOF
@@ -37,14 +37,6 @@ runs:
               - $(${{ inputs.cross-prefix }}gcc --version | grep -m1 "")
               - $(bash --version | grep -m1 "")
             EOF
-      - name: Set shell
-        shell: bash
-        run: |
-          if [[ ${{ inputs.nix-shell }} != '' ]]; then
-            echo SHELL="nix develop .#${{ inputs.nix-shell }} -c bash -e {0}" >> $GITHUB_ENV
-          else
-            echo SHELL="${{ inputs.custom_shell }}" >> $GITHUB_ENV
-          fi
       - name: Run functional tests
         id: func_test
         shell: ${{ env.SHELL }}

.github/actions/lint/action.yml

@@ -16,11 +16,10 @@ inputs:
 runs:
   using: composite
   steps:
-      - name: Setup nix
-        if: ${{ inputs.nix-shell != '' }}
-        uses: ./.github/actions/setup-nix
+      - uses: ./.github/actions/setup-shell
         with:
-          devShell: ${{ inputs.nix-shell }}
+          nix-shell: ${{ inputs.nix-shell }}
+          custom_shell: ${{ inputs.custom_shell }}
           script: |
             cat >> $GITHUB_STEP_SUMMARY << EOF
               ## Setup
@@ -31,14 +30,6 @@ runs:
               - $(${{ matrix.target.cross-prefix }}gcc --version | grep -m1 "")
               - $(bash --version | grep -m1 "")
             EOF
-      - name: Set shell
-        shell: bash
-        run: |
-          if [[ ${{ inputs.nix-shell }} != '' ]]; then
-            echo SHELL="nix develop .#${{ inputs.nix-shell }} -c bash -e {0}" >> $GITHUB_ENV
-          else
-            echo SHELL="${{ inputs.custom_shell }}" >> $GITHUB_ENV
-          fi
       - name: Run linter
         shell: ${{ env.SHELL }}
         run: |

.github/actions/setup-nix/action.yml

@@ -14,14 +14,39 @@ inputs:
 runs:
   using: composite
   steps:
-    - uses: DeterminateSystems/nix-installer-action@v14
+    - name: Pre-check nix
+      id: pre-check-nix
+      continue-on-error: true
+      shell: bash -leo pipefail {0}
+      run: |
+        . /nix/var/nix/profiles/default/etc/profile.d/nix-daemon.sh
+        nix --version
+        nix config show | grep -E "^trusted-users = .*$USER"
+        nix config show | grep -E "^experimental-features = .*flakes"
+        nix config show | grep -E "^experimental-features = .*nix-command"
+
+        echo SHELL="$(which nix) develop --quiet .#${{ inputs.devShell }} -c bash -e {0}" >> $GITHUB_ENV
+    - name: Install nix
+      if: steps.pre-check-nix.outcome == 'failure'
+      shell: bash -leo pipefail {0}
+      run: |
+        curl --proto '=https' --tlsv1.2 -sSf -L https://install.determinate.systems/nix | sh -s -- install --no-confirm \
+        --extra-conf "trusted-users = root ${USER:-}" \
+        --extra-conf "experimental-features = nix-command flakes"
+
+        . /nix/var/nix/profiles/default/etc/profile.d/nix-daemon.sh
+        echo SHELL="$(which nix) develop --quiet .#${{ inputs.devShell }} -c bash -e {0}" >> $GITHUB_ENV
+    - name: Post-check nix
+      continue-on-error: true
+      shell: bash -leo pipefail {0}
+      run: |
+        nix config check
     - uses: DeterminateSystems/magic-nix-cache-action@v8
+      continue-on-error: true
     - name: Prepare nix dev shell
-      shell: nix develop --quiet .#${{ inputs.devShell }} -c bash -e {0}
+      shell: ${{ env.SHELL }}
       run: |
     - name: Dependency check
-      shell: nix develop --quiet .#${{ inputs.devShell }} -c bash -e {0}
+      shell: ${{ env.SHELL }}
       if: inputs.script != ''
-      env:
-        INPUT_SCRIPT: ${{ inputs.script }}
-      run: eval "$INPUT_SCRIPT"
+      run: eval ${{ inputs.script }}

.github/actions/setup-shell/action.yml

@@ -0,0 +1,37 @@
+# SPDX-License-Identifier: Apache-2.0
+
+name: Set Shell
+description: Setup nix or custom shell for workflows
+
+inputs:
+  use-nix:
+    description: Indicate whether to use nix or not
+    default: 'true'
+  nix-shell:
+    description: Run in the specified Nix environment if exists
+    default: 'ci'
+  custom_shell:
+    description: The shell to use. Only relevant if no nix-shell specified
+    default: 'bash'
+  script:
+    description: The script to be run in the nix shell
+    required: false
+
+runs:
+  using: composite
+  steps:
+    - name: Setup nix
+      uses: ./.github/actions/setup-nix
+      if: ${{ inputs.use-nix == 'true' && env.SHELL == '' }}
+      with:
+        devShell: ${{ inputs.nix-shell }}
+        script: ${{ inputs.script }}
+    - name: Set custom shell
+      shell: bash
+      if: ${{ inputs.use-nix != 'true' && env.SHELL == '' }}
+      run: |
+          echo SHELL="${{ inputs.custom_shell }}" >> $GITHUB_ENV
+
+          if [[ "${{ inputs.script }}" != '' ]]; then
+            eval ${{ inputs.script }}
+          fi