Workflow: pre-install CPU torch from pytorch.org/whl/cpu (saves ~600MB)

.riahub/workflows/train.yaml

@@ -358,6 +358,10 @@ jobs:
           # only when the repo is genuinely installable (has setup.py /
           # setup.cfg, or pyproject.toml with [build-system]).
           cd "$WAVESFM_REPO_DIR"
+          # FAST-PATH: install CPU torch from pytorch.org/whl/cpu FIRST (~200MB).
+          # This makes torch==X already-satisfied so requirements.txt does not
+          # pull the 755MB manylinux wheel with bundled CUDA from PyPI default.
+          $PIP install --index-url https://download.pytorch.org/whl/cpu --extra-index-url https://pypi.org/simple torch==2.2.2 torchvision
           INSTALLED_SOMETHING=0
           if [[ -f requirements.txt ]]; then
             $PIP install -r requirements.txt
@@ -393,7 +397,8 @@ jobs:
             fi
           fi
           echo "Installing PyTorch from ${TORCH_INDEX_URL} (${TORCH_REASON})."
-          $PIP install --index-url "$TORCH_INDEX_URL" --upgrade --force-reinstall torch torchvision
+          # torch was pre-installed at the top of this step; no force-reinstall needed.
+          echo "Skipping torch force-reinstall (already installed at step head): $TORCH_INDEX_URL"
 
       - name: Find and adapt dataset
         shell: bash