Cannot create symlink inside shared folder on Windows host

[g_tirloni]

Symlinks do not work inside a VirtualBox Shared Folder when running on Windows 10 host with a Linux guest (Fedora 24)

$ mount  | grep vboxsf
home_vagrant_sync on /home/vagrant/sync type vboxsf (rw,nodev,relatime)
home_vagrant_sync on /home/vagrant/sync type vboxsf (rw,nodev,relatime)

$ pwd
/home/vagrant/sync
$ mkdir a
$ ln -s a b
ln: failed to create symbolic link 'b': Protocol error

Outside shared folder:

$ cd ..
$ pwd
/home/vagrant
$ mkdir c
$ ln -s c d
$ ls -ld d
lrwxrwxrwx 1 vagrant vagrant 1 Oct 12 20:51 d -> c

Environment:

$ uname -a
Linux guest 4.5.7-300.fc24.x86_64 #1 SMP Wed Jun 8 18:12:45 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux
$ VBoxClient --version
5.1.6r110634

>"C:\Program Files\Oracle\VirtualBox\VBoxManage.exe" --version
5.1.6r110634

[Socratis]

Unless you filed that as an enhancement, it is not a bug. It states so, clearly, in the User Manual, Chapter 4.3 Shared folders. I'll quote an excerpt from the relevant section. Please read the rest of it:

Starting with version 4.0, VirtualBox shared folders also support symbolic links (symlinks), under the following conditions:

1. The host operating system must support symlinks (i.e. a Mac, Linux or Solaris host is required).

[g_tirloni]

I considered it a bug since Windows supports ​symlinks, but according to the documentation I should have filed it as an enhacement, sorry about that.

If one would delve into the VirtualBox source code to try and implement this, any high-level advice on how to properly do it?