no panicwrap in plugins
no panicwrap in plugins

As of mitchellh/panicwrap#25, a call to panicwrap.Wrapped() unsets the
cookie in the env, that makes packer plugin child process inherit an env
without the panicwrap cookie and panicwrap itself.

This trips up CleanupClients() in Packer's plugin client: instead of the
real plugin server it now kills its panicwrap parent -- which doesn't
forward SIGKILL to its child because it's not a signal that can be
caught -- and ends up indefinitely waiting in client.Kill() for an EOF
that will never come.

This workaround is to not even try to panicwrap in a plugin server.

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