When using libvirt python you must never call the object constructors directly, as these are expecting to be passed a wrapped C object. For example import libvirt c = libvirt.virConnect("qemu:///system") c.listAllDomains() will mysteriously segfault. With this change the user now gets an slightly more helpful error Traceback (most recent call last): File "<stdin>", line 1, in <module> File "/home/berrange/src/virt/libvirt-python/build/libvirt.py", line 3409, in __init__ raise Exception("Expected a wrapped C Object but got %s" % type(_obj)) Exception: Expected a wrapped C Object but got <type 'str'> Signed-off-by: Daniel P. Berrange <berrange(a)redhat.com&gt; --- generator.py | 2 ++ 1 file changed, 2 insertions(+) diff --git a/generator.py b/generator.py index e9be8b1..6bcf80b 100755 --- a/generator.py +++ b/generator.py @@ -1532,6 +1532,8 @@ def buildWrappers(module): elif classname in [ "virDomainSnapshot" ]: classes.write(" self._dom = dom\n") classes.write(" self._conn = dom.connect()\n") + classes.write(" if type(_obj).__name__ not in [\"PyCapsule\", \"PyCObject\"]:\n") + classes.write(" raise Exception(\"Expected a wrapped C Object but got %s\" % type(_obj))\n") classes.write(" self._o = _obj\n\n") destruct=None if classname in classes_destructors: