Nix : Remove old channel before adding new one.

.config/bash/module/Nix.sh

@@ -20,11 +20,13 @@ function nix_find() {
 
 # Switch to Unstable branch.
 function nix_unstable() {
+	nix-channel --remove nixos
 	nix-channel --add https://nixos.org/channels/nixos-unstable nixos
 }
 
 # Switch to Small Unstable branch (for server).
 function nix_unstable_small() {
+	nix-channel --remove nixos
 	nix-channel --add https://nixos.org/channels/nixos-unstable-small nixos
 }
 
@@ -35,12 +37,12 @@ function nix_channel() {
 
 # Update system (rebuild).
 function nix_update() {
-	nixos-rebuild switch -I nixos-config=/root/.config/linux/nix/${HOSTNAME}/Configuration.nix
+	nixos-rebuild switch -I nixos-config=/root/.config/linux/system/${HOSTNAME}/Configuration.nix
 }
 
 # Upgrade system.
 function nix_upgrade() {
-	nixos-rebuild switch --upgrade -I nixos-config=/root/.config/linux/nix/${HOSTNAME}/Configuration.nix
+	nixos-rebuild switch --upgrade -I nixos-config=/root/.config/linux/system/${HOSTNAME}/Configuration.nix
 }
 
 # Free up root space.
@@ -49,6 +51,7 @@ function nix_clean() {
 	[[ "${UID}" = 0 ]] && nix-store --gc
 }
 
+# Spawn shell with nix environment, like LD support.
 function nix_shell() {
 	nix-shell ~/.config/linux/Shell.nix
 }