Stderr: VBoxManage.exe: error: Could not rename the directory

I am not a big fan of Vagrant, its behavior is way too erratic and opaque for me. When it works we are happy, when it fails - and it fails way too often - we are left googling sparse and stern documentation.

This new error "Stderr: VBoxManage.exe: error: Could not rename the directory" could be fixed only after LOTS of googling and trial and error:

Vagrant.configure("2") do |config2|
  # ... (other config)
  config2.vm.provider :virtualbox do |vb|
      vb.name = "jkstest"
  end
end

This should be added just after the config.vm.box_url clause, and BEFORE any customize.

How frustrating.

Despite this settings, my VB is created in C:\Users\myuser\VirtualBox VMs\workspaceJKS_1377339021, rather than in the jkstest folder.

The original error message was:

There was an error while executing `VBoxManage`, a CLI used by Vagrant
for controlling VirtualBox. The command and stderr is shown below.

Command: ["modifyvm", "3a81f6e5-ba5a-438b-85a8-501a63a3a053", "--name", "trunk_1377853840"]

Stderr: VBoxManage.exe: error: Could not rename the directory 'C:\Users\pippo\VirtualBox VMs\acme-basebox' to
'C:\Users\pippo\VirtualBox VMs\trunk_1377853840' to save the settings file (VERR_ACCESS_DENIED)
VBoxManage.exe: error: Details: code E_FAIL (0x80004005), component SessionMachine, interface IMachine, callee IUnknown
VBoxManage.exe: error: Context: "SaveSettings()" at line 2527 of file VBoxManageModifyVM.cpp

In fact, there was another VBOX running, which had been created with the name "acme-basebox" (this is the setting config.vm.box = "acme-basebox" . Shutting down this machine allowed me to start the other without the above mentioned hack.