Problem

You are trying to build a QEMU image with Packer, but you are getting the error suggesting to use the PACKER_LOG=1 option. But there is no indication where to place it in the command line.

Solution

Put it at the begging of the command line as folows:

kosmas:terraform (add_vault *%)$ PACKER_LOG=1 packer build vault_orchestration/template.json