Dmitry Nikolaev (2016-05-24 23:42 +0300) wrote:

> Second one gives
>
> guix system: error: service 'xorg-server' provided more than once

As I wrote in the previous message, I don't reproduce this.  Both
configs didn't give me any error, but when I added another (the second)
slim-service, then this error appears.  Are absolutely sure you specify
the right config for "guix system" command?

Can you try the attached config?  It is the same as yours, except I
commented non-free stuff from your modules, because I don't have them.
I ran the following command:

  guix system build --no-substitutes --dry-run --no-grafts .../attached-config.scm

and got no error (only a huge output of what would be built).  Is it
successful for you?