Try moving to Nix Experimental installer

action.yml

@@ -144,10 +144,10 @@ runs:
 
     - name: Install nix
       if: inputs.skip-nix-installation == 'false'
-      uses: DeterminateSystems/nix-installer-action@90bb610b90bf290cad97484ba341453bd1cbefea  # v19
+      uses: ./experimental-nix-installer
       with:
         logger: pretty
-        extra-conf: experimental-features = ca-derivations fetch-closure
+        extra-conf: experimental-features = ca-derivations fetch-closure nix-command flakes
 
     - name: Get nix version
       shell: bash

experimental-nix-installer/action.yml

@@ -0,0 +1,113 @@
+name: 'Experimental Nix Installer'
+description: 'Install Nix using the experimental installer'
+branding:
+  icon: 'box'
+  color: 'blue'
+
+inputs:
+  extra-conf:
+    description: 'Extra configuration to add to nix.conf'
+    default: ''
+  logger:
+    description: 'Logger format (compact, full, pretty)'
+    default: 'pretty'
+  nix-build-user-count:
+    description: 'Number of build users to create'
+    default: '32'
+  nix-build-group-name:
+    description: 'Name of the build group'
+    default: 'nixbld'
+  nix-build-group-id:
+    description: 'GID of the build group'
+    default: '30000'
+  modify-profile:
+    description: 'Modify user profile to set up environment'
+    default: 'true'
+  daemon:
+    description: 'Use daemon mode'
+    default: 'true'
+  init:
+    description: 'Init mode for installation'
+    default: 'systemd'
+  start-daemon:
+    description: 'Start the Nix daemon after installation'
+    default: 'true'
+  trust-runner-user:
+    description: 'Add runner user to trusted users'
+    default: 'true'
+  channels:
+    description: 'Nix channels to add'
+    default: 'nixpkgs=https://nixos.org/channels/nixpkgs-unstable'
+
+outputs:
+  nix-version:
+    description: 'The version of Nix that was installed'
+    value: ${{ steps.nix-install.outputs.nix-version }}
+
+runs:
+  using: "composite"
+  steps:
+    - name: Download and install experimental Nix installer
+      id: nix-install
+      shell: bash
+      env:
+        NIX_INSTALLER_EXTRA_CONF: ${{ inputs.extra-conf }}
+        NIX_INSTALLER_LOGGER: ${{ inputs.logger }}
+        NIX_INSTALLER_NIX_BUILD_USER_COUNT: ${{ inputs.nix-build-user-count }}
+        NIX_INSTALLER_NIX_BUILD_GROUP_NAME: ${{ inputs.nix-build-group-name }}
+        NIX_INSTALLER_NIX_BUILD_GROUP_ID: ${{ inputs.nix-build-group-id }}
+        NIX_INSTALLER_MODIFY_PROFILE: ${{ inputs.modify-profile }}
+        NIX_INSTALLER_INIT: ${{ inputs.init }}
+        NIX_INSTALLER_START_DAEMON: ${{ inputs.start-daemon }}
+        NIX_INSTALLER_TRUST_RUNNER_USER: ${{ inputs.trust-runner-user }}
+        NIX_INSTALLER_CHANNELS: ${{ inputs.channels }}
+      run: |
+        echo "Installing Nix using experimental installer..."
+
+        # Download and run the experimental installer
+        curl --proto '=https' --tlsv1.2 -sSf -L https://artifacts.nixos.org/experimental-installer | \
+          sh -s -- install --no-confirm
+
+        # Source the nix profile to make nix available in current shell
+        if [ -f ~/.nix-profile/etc/profile.d/nix.sh ]; then
+          source ~/.nix-profile/etc/profile.d/nix.sh
+        elif [ -f /etc/profile.d/nix.sh ]; then
+          source /etc/profile.d/nix.sh
+        fi
+
+        # Get Nix version and set output
+        NIX_VERSION=$(nix --version | awk '{print $NF}')
+        echo "nix-version=$NIX_VERSION" >> $GITHUB_OUTPUT
+        echo "Installed Nix version: $NIX_VERSION"
+
+        # Verify installation
+        nix --version
+        nix-env --version
+
+    - name: Add extra configuration
+      if: inputs.extra-conf != ''
+      shell: bash
+      run: |
+        echo "Adding extra Nix configuration..."
+        mkdir -p ~/.config/nix
+        echo "${{ inputs.extra-conf }}" >> ~/.config/nix/nix.conf
+        echo "Extra configuration added to nix.conf"
+
+    - name: Configure GitHub access token
+      if: github.server_url == 'https://github.com'
+      shell: bash
+      run: |
+        echo "Configuring GitHub access token for Nix..."
+        mkdir -p ~/.config/nix
+        echo "access-tokens = github.com=${{ github.token }}" >> ~/.config/nix/nix.conf
+        echo "GitHub access token configured"
+
+    - name: Verify Nix installation
+      shell: bash
+      run: |
+        echo "Verifying Nix installation..."
+        echo "Nix version: $(nix --version)"
+        echo "Nix store info:"
+        nix store info || echo "Store info not available"
+        echo "Nix channels:"
+        nix-channel --list || echo "No channels configured"