pkgs/nix-index: use cnf output similar to default NixOS one

pkgs/by-name/ni/nix-index/cnfOutput.patch

@@ -0,0 +1,66 @@
+diff --git a/command-not-found.sh b/command-not-found.sh
+index 5f30bad..3854297 100755
+--- a/command-not-found.sh
++++ b/command-not-found.sh
+@@ -73,51 +73,30 @@ EOF
+             else
+                 if [ -e "$HOME/.nix-profile/manifest.json" ]; then
+                     >&2 cat <<EOF
+-The program '$cmd' is currently not installed. You can install it
+-by typing:
+-  nix profile install $toplevel#$attrs
+-
+-Or run it once with:
+-  nix shell $toplevel#$attrs -c $cmd ...
++The program '$cmd' is not in your PATH. You can make it available in an
++ephemeral shell by typing:
++  nix shell $toplevel#$attrs
+ EOF
+                 else
+                     >&2 cat <<EOF
+-The program '$cmd' is currently not installed. You can install it
+-by typing:
+-  nix-env -iA $toplevel.$attrs
+-
+-Or run it once with:
+-  nix-shell -p $attrs --run '$cmd ...'
++The program '$cmd' is not in your PATH. You can make it available in an
++ephemeral shell by typing:
++  nix-shell -p $attrs
+ EOF
+                 fi
+             fi
+             ;;
+         *)
+             >&2 cat <<EOF
+-The program '$cmd' is currently not installed. It is provided by
+-several packages. You can install it by typing one of the following:
+-EOF
+-
+-            # ensure we get each element of attrs
+-            # in a cross platform way
+-            while read attr; do
+-                if [ -e "$HOME/.nix-profile/manifest.json" ]; then
+-                    >&2 echo "  nix profile install $toplevel#$attr"
+-                else
+-                    >&2 echo "  nix-env -iA $toplevel.$attr"
+-                fi
+-            done <<< "$attrs"
+-
+-            >&2 cat <<EOF
+-
+-Or run it once with:
++The program '$cmd' is not in your PATH. You can make it available in an
++ephemeral shell by typing:
+ EOF
+ 
+             while read attr; do
+                 if [ -e "$HOME/.nix-profile/manifest.json" ]; then
+-                    >&2 echo "  nix shell $toplevel#$attr -c $cmd ..."
++                    >&2 echo "  nix shell $toplevel#$attr"
+                 else
+-                    >&2 echo "  nix-shell -p $attr --run '$cmd ...'"
++                    >&2 echo "  nix-shell -p $attr"
+                 fi
+             done <<< "$attrs"
+             ;;

pkgs/by-name/ni/nix-index/override.nix

@@ -0,0 +1,9 @@
+{self, super, package }:
+
+package.override {
+  nix-index-unwrapped = self.nix-index-unwrapped.overrideAttrs (oldAttrs: {
+    patches = oldAttrs.patches or [] ++ [
+      ./cnfOutput.patch
+    ];
+  });
+}