Vagrant SSH Agent Forwarding + Provider Config = Error?

Question

Relative Vagrant and Ruby newb here. I'm trying to enable SSH forwarding from my Windows machine to my Vagrant created Ubuntu VM. My Vagrantfile has some Virtualbox provider specific config:

  config.vm.provider "virtualbox" do |v|
    v.name = guestHostname
    v.memory = 8192
    v.cpus = 2
    v.customize ["modifyvm", :id, "--vram", "128"]
    v.gui = true
  end

Works fine by itself. But when I add the config for SSH forwarding:

  config.ssh.forward_agent = true

Running 'vagrant up' starts failing with this error message:

Bringing machine 'development' up with 'virtualbox' provider...
==> development: Importing base box 'bento/ubuntu-16.10'...
==> development: Matching MAC address for NAT networking...
==> development: Checking if box 'bento/ubuntu-16.10' is up to date...
==> development: Setting the name of the VM: development
==> development: Clearing any previously set network interfaces...
==> development: Preparing network interfaces based on configuration...
    development: Adapter 1: nat
==> development: Forwarding ports...
    development: 22 (guest) => 2222 (host) (adapter 1)
==> development: Running 'pre-boot' VM customizations...
==> development: Booting VM...
==> development: Waiting for machine to boot. This may take a few minutes...
    development: SSH address: 127.0.0.1:2222
    development: SSH username: vagrant
    development: SSH auth method: private key
==> development: Forcing shutdown of VM...
==> development: Destroying VM and associated drives...
C:/HashiCorp/Vagrant/embedded/gems/gems/net-ssh-4.1.0/lib/net/ssh/transport/server_version.rb:54:in `readpartial': An established connection was aborted by the software in your host machine. (Errno::ECONNABORTED)
        from C:/HashiCorp/Vagrant/embedded/gems/gems/net-ssh-4.1.0/lib/net/ssh/transport/server_version.rb:54:in `block (2 levels) in negotiate!'
        from C:/HashiCorp/Vagrant/embedded/gems/gems/net-ssh-4.1.0/lib/net/ssh/transport/server_version.rb:52:in `loop'
        from C:/HashiCorp/Vagrant/embedded/gems/gems/net-ssh-4.1.0/lib/net/ssh/transport/server_version.rb:52:in `block in negotiate!'
        from C:/HashiCorp/Vagrant/embedded/gems/gems/net-ssh-4.1.0/lib/net/ssh/transport/server_version.rb:50:in `loop'
        from C:/HashiCorp/Vagrant/embedded/gems/gems/net-ssh-4.1.0/lib/net/ssh/transport/server_version.rb:50:in `negotiate!'
        from C:/HashiCorp/Vagrant/embedded/gems/gems/net-ssh-4.1.0/lib/net/ssh/transport/server_version.rb:32:in `initialize'
        from C:/HashiCorp/Vagrant/embedded/gems/gems/net-ssh-4.1.0/lib/net/ssh/transport/session.rb:84:in `new'
        from C:/HashiCorp/Vagrant/embedded/gems/gems/net-ssh-4.1.0/lib/net/ssh/transport/session.rb:84:in `initialize'
        from C:/HashiCorp/Vagrant/embedded/gems/gems/net-ssh-4.1.0/lib/net/ssh.rb:233:in `new'
        from C:/HashiCorp/Vagrant/embedded/gems/gems/net-ssh-4.1.0/lib/net/ssh.rb:233:in `start'
        from C:/HashiCorp/Vagrant/embedded/gems/gems/vagrant-1.9.4/plugins/communicators/ssh/communicator.rb:397:in `block (2 levels) in connect'
        from C:/HashiCorp/Vagrant/embedded/lib/ruby/2.2.0/timeout.rb:88:in `block in timeout'
        from C:/HashiCorp/Vagrant/embedded/lib/ruby/2.2.0/timeout.rb:32:in `block in catch'
        from C:/HashiCorp/Vagrant/embedded/lib/ruby/2.2.0/timeout.rb:32:in `catch'
        from C:/HashiCorp/Vagrant/embedded/lib/ruby/2.2.0/timeout.rb:32:in `catch'
        from C:/HashiCorp/Vagrant/embedded/lib/ruby/2.2.0/timeout.rb:103:in `timeout'
        from C:/HashiCorp/Vagrant/embedded/gems/gems/vagrant-1.9.4/plugins/communicators/ssh/communicator.rb:371:in `block in connect'
        from C:/HashiCorp/Vagrant/embedded/gems/gems/vagrant-1.9.4/lib/vagrant/util/retryable.rb:17:in `retryable'
        from C:/HashiCorp/Vagrant/embedded/gems/gems/vagrant-1.9.4/plugins/communicators/ssh/communicator.rb:370:in `connect'
        from C:/HashiCorp/Vagrant/embedded/gems/gems/vagrant-1.9.4/plugins/communicators/ssh/communicator.rb:68:in `block in wait_for_ready'
        from C:/HashiCorp/Vagrant/embedded/lib/ruby/2.2.0/timeout.rb:88:in `block in timeout'
        from C:/HashiCorp/Vagrant/embedded/lib/ruby/2.2.0/timeout.rb:32:in `block in catch'
        from C:/HashiCorp/Vagrant/embedded/lib/ruby/2.2.0/timeout.rb:32:in `catch'
        from C:/HashiCorp/Vagrant/embedded/lib/ruby/2.2.0/timeout.rb:32:in `catch'
        from C:/HashiCorp/Vagrant/embedded/lib/ruby/2.2.0/timeout.rb:103:in `timeout'
        from C:/HashiCorp/Vagrant/embedded/gems/gems/vagrant-1.9.4/plugins/communicators/ssh/communicator.rb:46:in `wait_for_ready'
        from C:/HashiCorp/Vagrant/embedded/gems/gems/vagrant-1.9.4/lib/vagrant/action/builtin/wait_for_communicator.rb:16:in `block in call'

Commenting out the provider specific config makes the error go away, and forwarding appears to work. Any ideas on what could be causing the issue?

Answer 1

I can see that you are using vagrant 1.9.4 and this is a known issue with vagrant 1.9.4. I am linking here the github issue associated with this problem. This has been fixed in version 1.9.5 though. So, you could either downgrade to 1.9.3 or upgrade to 1.9.5