try spack caching again

.github/actions/dependencies/action.yml

@@ -10,6 +10,10 @@ inputs:
     description: 'Secrets to pass to the action'
     required: false
     default: ''
+  spack_version:
+    description: 'Version of Spack to use'
+    required: false
+    default: '2024-11-13'
 
 runs:
   using: 'composite'
@@ -18,7 +22,39 @@ runs:
       if: startsWith(runner.os, 'macos')
       shell: bash
       run: |
-        brew install ninja ccache
+        brew install ninja ccache zstd
+
+    - name: Restore cache
+      id: cache-restore
+      uses: actions/cache/restore@v3
+      with:
+        path: spack.tar.zst
+        key: spack-${{ runner.os }}-${{ inputs.spack_version }}-${{ hashFiles('CI/dependencies/setup_spack.sh') }}
+
+    - name: Extract cached Spack
+      if: steps.cache-restore.outputs.cache-hit == 'true'
+      shell: bash
+      run: |
+        zstd -d spack.tar.zst -f
+        tar xf spack.tar
+        rm spack.tar
+
+    - name: Setup Spack from scratch
+      if: steps.cache-restore.outputs.cache-hit != 'true'
+      shell: bash
+      env:
+        SPACK_VERSION: ${{ inputs.spack_version }}
+      run: |
+        CI/dependencies/setup_spack.sh
+        tar cf spack.tar spack/
+        zstd -19 --rm spack.tar
+
+    - name: Save cache
+      if: steps.cache-restore.outputs.cache-hit != 'true'
+      uses: actions/cache/save@v3
+      with:
+        path: spack.tar.zst
+        key: spack-${{ runner.os }}-${{ inputs.spack_version }}-${{ hashFiles('CI/dependencies/setup_spack.sh') }}
 
     - name: Install dependencies
       shell: bash

CI/dependencies/setup.sh

@@ -100,26 +100,12 @@ mkdir -p ${destination}
 
 start_section "Install spack if not already installed"
 if ! command -v spack &> /dev/null; then
-    if [ ! -d "spack" ]; then
-        echo "Cloning spack"
-        git clone -c feature.manyFiles=true https://github.com/spack/spack.git
-        pushd spack > /dev/null
-        git config user.name github-actions[bot]
-        git config user.email 41898282+github-actions[bot]@users.noreply.github.com
-        # Apply patch for spack improvements
-        curl https://patch-diff.githubusercontent.com/raw/spack/spack/pull/47370.patch | git am
-        popd > /dev/null
-    else
-        echo "Updating spack"
-        pushd spack > /dev/null
-        git pull --rebase
-        popd > /dev/null
-    fi
-
-    source "$(pwd)/spack/share/spack/setup-env.sh"
+  "${SCRIPT_DIR}/setup_spack.sh"
 fi
 end_section
 
+source "$(pwd)/spack/share/spack/setup-env.sh"
+
 if [ -n "${CI:-}" ]; then
 start_section "Add buildcache mirror"
 mirror_name="acts-spack-buildcache"

CI/dependencies/setup_spack.sh

@@ -0,0 +1,20 @@
+#!/bin/bash
+
+_spack_version=${SPACK_VERSION:-develop}
+
+if [ ! -d "spack" ]; then
+    echo "Cloning spack"
+    git clone -c feature.manyFiles=true https://github.com/spack/spack.git -b ${_spack_version}
+    pushd spack > /dev/null
+    git config user.name CI
+    git config user.email <>
+    echo "Applying patch for spack improvements"
+    curl https://patch-diff.githubusercontent.com/raw/spack/spack/pull/47370.patch | git am
+    curl https://patch-diff.githubusercontent.com/raw/spack/spack/pull/48236.patch | git am
+
+    rm -rf .git
+
+    echo "Populating the repository index"
+    bin/spack list > /dev/null
+    popd > /dev/null
+fi