Não consigo prover uma pasta para a VM

Vagrant.configure("2") do |config|
  config.vm.box = "ubuntu/bionic64"
  config.vm.network "forwarded_port", guest: 80, host: 8089
  config.vm.network "public_network", ip: "192.168.15.5"
  config.vm.synced_folder "./configs", "/configs"
  config.vm.provision "shell",
  inline: "cat /configs/key_bionic.pub >> .ssh/authorized_keys"
  end

azos@ruindows MINGW64 /c/ambiente_dev/bionic
$ vagrant provision
==> default: Running provisioner: shell...
    default: Running: inline script
    default: cat:
    default: /configs/key_bionic.pub
    default: : No such file or directory
The SSH command responded with a non-zero exit status. Vagrant
assumes that this means the command failed. The output for this command
should be in the log above. Please read the output to determine what
went wrong.

A pasta existe: C:\ambiente_dev\bionic\configs e o arquivo key_bionic.pub tambem.

azos@ruindows MINGW64 /c/ambiente_dev/bionic/configs
$ ls
  key_bionic.pub