nixos systemPackages: rework default outputs

- Now `pkg.outputUnspecified = true` but this attribute is missing in
  every output, so we can recognize whether the user chose or not.
  If (s)he didn't choose, we put `pkg.bin or pkg.out or pkg` into
  `systemPackages`.
- `outputsToLink` is replaced by `extraOutputsToLink`.
  We add extra outputs *regardless* of whether the user chose anything.
  It's mainly meant for outputs with docs and debug symbols.
- Note that as a result, some libraries will disappear from system path.

1 files changed, 1 insertions, 1 deletions

diff --git a/lib/customisation.nix b/lib/customisation.nix
index 585495469b2..efe82d78660 100644
--- a/lib/customisation.nix
+++ b/lib/customisation.nix
@@ -129,7 +129,7 @@ rec {
         };
 
       outputsList = map outputToAttrListElement outputs;
-  in commonAttrs.${drv.outputName};
+  in commonAttrs // { outputUnspecified = true; };
 
 
   /* Strip a derivation of all non-essential attributes, returning