TorchScript bad_alloc issue (pytorch#2542)

Summary: Pull Request resolved: pytorch#2542

Differential Revision: D65495806

Author: PaulZhang12

.github/workflows/unittest_ci_cpu.yml

@@ -45,9 +45,9 @@ jobs:
         conda info
         python --version
         conda run -n build_binary python --version
-        conda install -n build_binary \
+        conda run -n build_binary \
           --yes \
-          pytorch cpuonly -c pytorch-nightly
+          pip install --pre torch --index-url https://download.pytorch.org/whl/nightly/cpu
         conda run -n build_binary \
           python -c "import torch.distributed"
         conda run -n build_binary \