repo fail to init on Ubuntu 16,0 virtual box on Macbook

I am trying to build AOSP image on my mac Book using Linux virtual box.

Since I don’t have enough space on Mac I am trying to checkoutAOSP on external 2 TB Segate HDD which I planned to use for build.

I have installed repo tool and python 2.7 but when I try to init repo with this command

repo init -u https://android.googlesource.com/platform/manifest

It fail with this error message

hitesh@hitesh-VirtualBox:/media/hitesh/2TB/test$ repo init -u https://android.googlesource.com/platform/manifest
Get https://android.googlesource.com/platform/manifest
Traceback (most recent call last):
  File "/media/hitesh/2TB/test/.repo/repo/main.py", line 531, in <module>
    _Main(sys.argv[1:])
  File "/media/hitesh/2TB/test/.repo/repo/main.py", line 507, in _Main
    result = repo._Run(argv) or 0
  File "/media/hitesh/2TB/test/.repo/repo/main.py", line 180, in _Run
    result = cmd.Execute(copts, cargs)
  File "/media/hitesh/2TB/test/.repo/repo/subcmds/init.py", line 399, in Execute
    self._SyncManifest(opt)
  File "/media/hitesh/2TB/test/.repo/repo/subcmds/init.py", line 171, in _SyncManifest
    m._InitGitDir(mirror_git=mirrored_manifest_git)
  File "/media/hitesh/2TB/test/.repo/repo/project.py", line 2292, in _InitGitDir
    self._UpdateHooks()
  File "/media/hitesh/2TB/test/.repo/repo/project.py", line 2312, in _UpdateHooks
    self._InitHooks()
  File "/media/hitesh/2TB/test/.repo/repo/project.py", line 2341, in _InitHooks
    os.symlink(os.path.relpath(stock_hook, os.path.dirname(dst)), dst)
OSError: [Errno 38] Function not implemented

I dont know how to trouble shoot this, I dont understand which function is not implemented,

Answer

I figured it out repo cant be initialise on an external hdd. I had to create a vdi file on my external hard disk and then use that to download aosp source code.