Many libvirt-tck tests do not explicitly cleanup test domains before exiting. In this case Sys::Virt::TCK->cleanup is triggered, and the environment is reset automatically. During this reset, any existing snapshots are found for deletion through Sys::Virt::Domain->list_snapshots. If the underlying connection driver does not support snapshot functions (such as lxc or libxl), the process dies with the following error: libvirt error code: 3, message: this function is not supported by the connection driver: virDomainSnapshotListNames The best resolution would be to add snapshot support to the driver(s), but as this requires a long term effort, it is better to catch the error and return an empty list of snapshots to the calling function. In the case of libvirt-tck, this allows the cleanup to succeed and subsequent testing to continue normally. --- Domain.pm | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/lib/Sys/Virt/Domain.pm 2014-04-07 04:35:31.000000000 -0600 +++ b/lib/Sys/Virt/Domain.pm 2014-04-21 13:48:22.868956838 -0600 @@ -1416,7 +1416,10 @@ recommended as a more efficient alternat sub list_snapshots { my $self = shift; - my $nnames = $self->num_of_snapshots(); + # If snapshots are not supported by the driver (lxc, libxl...), catch the + # function not supported error and simply return as there are no snapshots + my $nnames = eval { $self->num_of_snapshots() }; + return if($@ =~ /function is not supported/); my @names = $self->list_snapshot_names($nnames);