scripts: Clean up, add root check

- Add `set -euo pipefail` to several scripts which were missing it
- Add a check for if `nix-setup` is running as root and exit if so

software/scripts/clean.sh

@@ -1,5 +1,5 @@
 #! /usr/bin/env bash
-set -e
+set -euo pipefail
 
 shopt -s globstar # Enable globstar for recursive globbing
 

software/scripts/nix-package.sh

@@ -1,6 +1,6 @@
 #!/usr/bin/env bash
 
-set -e
+set -euo pipefail
 
 # cd to the software directory
 cd "$(git rev-parse --show-toplevel)"/software

software/scripts/nix-setup.sh

@@ -1,6 +1,12 @@
 #!/usr/bin/env bash
 
-set -e
+set -euo pipefail
+
+# exit if run as root
+if [ "$EUID" -eq 0 ]; then
+  echo "Please run as yourself! Running as superuser (ie, with sudo) breaks the setup."
+  exit
+fi
 
 echo "Setting up git submodule repos"