[ash2] jenkins@b-imagebuilder-worker-r13h17-prod:~/workspace/imagebuilder/packer/output$ virt-sparsify --compress  /data/home/jenkins/workspace/imagebuilder/packer/output/packer-vm.qcow2 /data/home/jenkins/workspace/imagebuilder/packer/output/packer-vm.qcow2.sparsified

Input disk virtual size = 41943040000 bytes (39.1G)

Create overlay file in /data/tmp/ to protect source disk ...

Examine source disk ...

Fatal error: exception Guestfs.Error("guestfs_launch failed.

This usually means the libguestfs appliance failed to start or crashed.

See http://libguestfs.org/guestfs-faq.1.html#debugging-libguestfs

or run 'libguestfs-test-tool' and post the *complete* output into a

bug report