propertly check and source additional env files

dot_config/environment

@@ -1,11 +1,16 @@
 #!/bin/sh
 
-# icky, but necessary since this might inject the needed XDG vars
-. "$HOME/.config/environment.local" 2>/dev/null
-. "$XDG_DATA_HOME/cargo/env" 2>/dev/null
+# Function to source a file only if it exists
+maybe_source() {
+    for file in "$@"; do
+        [ -f "$file" ] && . "$file"
+    done
+}
 
-# nix home-manager
-. "$HOME/.nix-profile/etc/profile.d/hm-session-vars.sh"
+maybe_source "$HOME/.config/environment.local"
+maybe_source "$XDG_DATA_HOME/cargo/env"
+maybe_source "$HOME/.nix-profile/etc/profile.d/nix.sh"
+maybe_source "$HOME/.nix-profile/etc/profile.d/hm-session-vars.sh"
 
 # set to defaults if any of these are unset
 export XDG_DATA_HOME="${XDG_DATA_HOME:-$HOME/.local/share}"