fix buildOn=auto detection

Author: Mic92

src/nixos-anywhere.sh

@@ -545,13 +545,15 @@ checkBuildLocally() {
 
   local entropy
   entropy="$(date +'%Y%m%d%H%M%S')"
+
   if nix build \
     -L \
     "${nixOptions[@]}" \
     --expr \
     "derivation { system = \"$system\"; name = \"env-$entropy\"; builder = \"/bin/sh\"; args = [ \"-c\" \"echo > \$out\" ]; }"; then
     # The local build failed
     buildOn=local
+    return
   fi
 
   buildOn=remote