make friendly error message (#9605)
make friendly error message (#9605)


ricardclau/packer,hashicorp/packer,ricardclau/packer,ricardclau/packer,pecigonzalo/packer,rnaveiras/packer,rnaveiras/packer,rnaveiras/packer,pecigonzalo/packer,pecigonzalo/packer,hashicorp/packer,rnaveiras/packer,rnaveiras/packer,mitchellh/packer,pecigonzalo/packer,rnaveiras/packer,ricardclau/packer,mitchellh/packer,hashicorp/packer,mitchellh/packer,hashicorp/packer,mitchellh/packer,ricardclau/packer,mitchellh/packer,ricardclau/packer