ci: Re-enable conda env caching with stable path

Author: hansungk

.github/scripts/setup-chipyard.sh

@@ -11,11 +11,13 @@ cd "${CHIPYARD_DIR}"
 
 if [[ "${CACHE_HIT}" == "true" ]]; then
     echo "[CI] Cache hit! Skipping conda and toolchain steps"
-    export RISCV="${CHIPYARD_DIR}/.conda-env/riscv-tools"
+    export RISCV="${CHIPYARD_CONDA_ENV_PATH}/riscv-tools"
     [ -d "${RISCV}" ] || ( echo "error: ${RISCV} does not exist!" && exit 1 )
     source $(conda info --base)/etc/profile.d/conda.sh
-    conda activate "${CHIPYARD_DIR}/.conda-env"
-    ./build-setup.sh riscv-tools --skip-conda --skip-toolchain --skip-precompile --skip-firesim --skip-marshal
+    conda activate "${CHIPYARD_CONDA_ENV_PATH}"
+    ./build-setup.sh riscv-tools --conda-env-name "${CHIPYARD_CONDA_ENV_NAME}" \
+        --skip-conda --skip-toolchain --skip-precompile --skip-firesim --skip-marshal
 else
-    ./build-setup.sh riscv-tools --skip-precompile --skip-firesim --skip-marshal
+    ./build-setup.sh riscv-tools --conda-env-name "${CHIPYARD_CONDA_ENV_NAME}" \
+        --skip-precompile --skip-firesim --skip-marshal
 fi

.github/workflows/ci.yml

@@ -41,6 +41,8 @@ jobs:
           git clone --depth 1 --branch graphics "https://github.com/ucb-bar/chipyard.git" "${CHIPYARD_DIR}"
           cd "${CHIPYARD_DIR}"
           echo "CHIPYARD_HASH=$(git rev-parse HEAD)" >> "${GITHUB_ENV}"
+          # cross-workflow shared conda env
+          echo "CHIPYARD_CONDA_ENV_NAME=chipyard-$(git rev-parse HEAD)" >> "${GITHUB_ENV}"
           # for caching
           ln -sf "${CHIPYARD_DIR}" "${GITHUB_WORKSPACE}/${CHIPYARD_RELPATH}"
 
@@ -51,6 +53,11 @@ jobs:
           auto-activate-base: true
           activate-environment: ""
 
+      - name: Setup conda env path
+        run: |
+          set -x
+          echo "CHIPYARD_CONDA_ENV_PATH=$(conda info --base)/${CHIPYARD_CONDA_ENV_NAME} >> ${GITHUB_ENV}"
+
       - name: Install cargo
         uses: dtolnay/rust-toolchain@stable
 
@@ -65,14 +72,14 @@ jobs:
             ~/.cache/coursier
           key: scala-${{ hashFiles('**/*.sbt', '**/project/**') }}-${{ runner.os }}-${{ runner.arch }}-${{ env.CACHE_NUMBER }}
 
-      # - name: Cache conda-env
-      #   id: cache-conda-env
-      #   uses: actions/cache@v5
-      #   with:
-      #     path: |
-      #       ${{ env.CHIPYARD_RELPATH }}/.conda-env
-      #       ${{ env.CHIPYARD_RELPATH }}/env.sh
-      #     key: chipyard-${{ env.CHIPYARD_HASH }}-${{ runner.os }}-${{ runner.arch }}-${{ env.CACHE_NUMBER }}
+      - name: Cache conda-env
+        id: cache-conda-env
+        uses: actions/cache@v5
+        with:
+          path: |
+            ${{ env.CHIPYARD_CONDA_ENV_PATH }}
+            ${{ env.CHIPYARD_RELPATH }}/env.sh
+          key: chipyard-${{ env.CHIPYARD_HASH }}-${{ runner.os }}-${{ runner.arch }}-${{ env.CACHE_NUMBER }}
 
       - name: Setup Chipyard
         run: |
@@ -139,7 +146,8 @@ jobs:
     needs: [run-soc-isa-tests, run-core-isa-tests, run-cosim-isa-tests]
     if: always()
     steps:
-      - name: Cleanup workspace and chipyard
+      - name: Cleanup workspace, chipyard and conda
         run: |
           [ -d "${{ github.workspace }}" ] && rm -rf "${{ github.workspace }}"
           [ -d "${CHIPYARD_DIR}" ] && rm -rf "${CHIPYARD_DIR}"
+          [ -d "${CHIPYARD_CONDA_ENV_PATH}" ] && rm -rf "${CHIPYARD_CONDA_ENV_PATH}"