do this with a trap

Signed-off-by: fbt <fbt@fleshless.org>

autobuilder/build

@@ -1,6 +1,10 @@
 #!/usr/bin/env bash
 shopt -s nullglob
 
+cleanup() {
+	chown -R root:root /buildroot
+}
+
 # Upgrade
 pacman -Suy --noconfirm
 
@@ -9,9 +13,12 @@ useradd -U builder
 builder_uid=$(id -u builder)
 builder_gid=$(id -g builder)
 
-# gnupg dir permissions
+# dir permissions
 chown -R "$builder_uid:$builder_gid" /.gnupg /buildroot
 
+# Return the permissions on exit
+trap cleanup INT TERM EXIT
+
 # Add sudo permissions for pacman to install dependencies
 printf '%s ALL=(ALL) NOPASSWD: /usr/bin/pacman\n' 'builder' > /etc/sudoers.d/builduser
 
@@ -25,5 +32,4 @@ deps=( ./deps/* )
 # Build the damn thing
 sudo -u builder GNUPGHOME="/.gnupg" makepkg "$@"
 
-# Return the permissions
 chown -R root:root /buildroot