lvm and thin_dump

[areq]

I try to make differential copies of lvm thin snapshots with thin_delta and thin_dump.

 # ls -al /dev/mapper/pve-vz*
lrwxrwxrwx 1 root root 7 Jul 19 23:09 /dev/mapper/pve-vz -> ../dm-3
lrwxrwxrwx 1 root root 7 Sep  1 10:46 /dev/mapper/pve-vz_tdata -> ../dm-1
lrwxrwxrwx 1 root root 7 Sep  1 10:46 /dev/mapper/pve-vz_tmeta -> ../dm-0
lrwxrwxrwx 1 root root 7 Sep  1 10:46 /dev/mapper/pve-vz-tpool -> ../dm-2

# dmsetup message /dev/mapper/pve-vz-tpool  0 reserve_metadata_snap

# thin_dump -m /dev/mapper/pve-vz_tmeta
thin_dump: /usr/include/boost/smart_ptr/shared_ptr.hpp:710: typename boost::detail::sp_member_access<T>::type boost::shared_ptr<T>::operator->() const [with T = persistent_data::checked_space_map; typename boost::detail::sp_member_access<T>::type = persistent_data::checked_space_map*]: Assertion `px != 0' failed.
Aborted

What I did wrong?

 

[areq]

debian package thin-provisioning-tools 0.6.1-4+b1 was a source of problems. thin_dump 0.7.1 compiled from git works fine.