> Hi Stephane,
>
> as you can tell from page you linked to the link you posted VirtualBox
> is placed in the 'contrib' section, which you did not enable for the
> ascii-* stanzas in your sources.list.
>
> HTH, best regards
> Urban


Hi, yeah thanks, I was surprised that it would be in main section since
it's not a perfectly GPL freedom compliant software... but we need to
open the details page of the package to be sure of this, Devuan package
website is very far below from the Debian one.

So it finally worked thanks to your advice and then I just had to
install "virtualbox" package to have the latest available one.

But now I'm stuck with a similar problem for "linux-compiler-gcc-6-x86
4.16.16-2~bpo9+1 [kernel - optional]"

It is needed but I can't install it because when I "aptitude search 
linux-compiler" I get:
i A linux-compiler-gcc-4.8-x86 
                                           - Compiler for Linux on x86 
(meta-package) 

i   linux-compiler-gcc-6-x86 
                                           - Compiler for Linux on x86 
(meta-package)

When I install linux-compiler-gcc-6-x86 I get:
  ii  linux-compiler-gcc-6-x86               4.9.110-1 
        amd64

I can't get the 4.16 one, please help!!!

--
Cordialement, Stephane Ascoet