+sometimes. This appears to happen (only?) if the main program
+segfaults.
+
+[libguestfs] qemu process not cleaned up occasionally. This appears
+to happen only if the main program or library segfaults, in which case
+the atexit handler which would normally perform cleanup is not run.
+sometimes. This appears to happen (only?) if the main program
+segfaults.
+[testing a hacky fix to this]