Don't silently ignore errors from the activation script

nixos/modules/installer/tools/nixos-rebuild.sh

@@ -225,7 +225,10 @@ fi
 # If we're not just building, then make the new configuration the boot
 # default and/or activate it now.
 if [ "$action" = switch -o "$action" = boot -o "$action" = test ]; then
-    $pathToConfig/bin/switch-to-configuration "$action"
+    if ! $pathToConfig/bin/switch-to-configuration "$action"; then
+        echo "warning: there were error switching to the new configuration" >&2
+        exit 1
+    fi
 fi
 
 

nixos/modules/security/setuid-wrappers.nix

@@ -97,8 +97,7 @@ in
           }:
 
           ''
-            source=${if source != "" then source else "$(PATH=$SETUID_PATH type -tP ${program})"}
-            if test -z "$source"; then
+            if ! source=${if source != "" then source else "$(PATH=$SETUID_PATH type -tP ${program})"}; then
                 # If we can't find the program, fall back to the
                 # system profile.
                 source=/nix/var/nix/profiles/default/bin/${program}

nixos/modules/system/activation/activation-script.nix

@@ -66,6 +66,9 @@ in
                 PATH=$PATH:$i/bin:$i/sbin
             done
 
+            _status=0
+            trap "_status=1" ERR
+
             # Ensure a consistent umask.
             umask 0022
 
@@ -84,6 +87,8 @@ in
 
             # Prevent the current configuration from being garbage-collected.
             ln -sfn /run/current-system /nix/var/nix/gcroots/current-system
+
+            exit $_status
           '';
       };