Hello.

I have exactly the same problem:
Quote:

*** ERROR: root could not be created.
create a symbolic linking for Vc library ....
libVc.a not found in lib dirctory
*** End installation of external packages with Errors***

I'm trying to compile the external packages in a Debian testing amd64 machine; using gcc-4.9.2 (there are problems between gcc-5 or gcc-6 and root6) If I run git log in /tools/root I get:

commit 86108d5adde6979551fcbf3d95012f72653dd102
Author: Pere Mato <pere.mato@cern.ch>
Date:   Thu Mar 3 10:36:03 2016 +0100

    Update ROOT version files to v6.06/02.