Sh bad substition error

[sean-smith]

If you see the following error when building a dockerfile:

sh: 1: Bad substitution

It's likely caused by your dockerfile running sh and not bash which doesn't support variables with v. such as the version of AWS OFI NCCL:

awsome-distributed-training/3.test_cases/1.megatron-lm/0.distributed-training.Dockerfile

Line 71 in 9fc4e12

&& git checkout ${AWS_OFI_NCCL_VERSION} \

The solution is to set the shell in your Dockerfile:

SHELL ["/bin/bash", "-c"]