diff --git a/dangerzone/container.py b/dangerzone/container.py
index f7131a9..520979e 100644
--- a/dangerzone/container.py
+++ b/dangerzone/container.py
@@ -236,7 +236,7 @@ def convert(vm_info_path, input_filename, output_filename, ocr, ocr_lang):
         vm_rmdir(pixel_dir, vm_info)
         vm_rmdir(safe_dir, vm_info)
 
-        return ret
+        sys.exit(ret)
 
     else:
         print("not implemented yet")
diff --git a/dangerzone/gui/tasks.py b/dangerzone/gui/tasks.py
index 44e379a..f86b820 100644
--- a/dangerzone/gui/tasks.py
+++ b/dangerzone/gui/tasks.py
@@ -37,6 +37,7 @@ class TaskBase(QtCore.QThread):
 
             self.update_details.emit(output)
 
+        print(f"return code: {p.returncode}")
         if p.returncode == 126 or p.returncode == 127:
             self.task_failed.emit(f"Authorization failed")
         elif p.returncode != 0:
diff --git a/install/vm-builder/build-iso.sh b/install/vm-builder/build-iso.sh
index e314726..abdae3d 100755
--- a/install/vm-builder/build-iso.sh
+++ b/install/vm-builder/build-iso.sh
@@ -5,9 +5,7 @@ sudo modprobe fuse
 sudo modprobe tun
 sudo rc-update add cgroups
 sudo rc-service cgroups start
-
-# Temporarily comment this out to speed up building ISOs in dev
-# sudo -u user podman system prune -a -f
+sudo -u user podman system prune -a -f
 
 # Build the podman container
 cd /opt/dangerzone-converter