Remote: Using a pure-python msgpack! This will result in lower performance
On CentOS: try installing python34-msgpack?
Connection closed by remote host. Is borg working on the server?
maybe you're using '@borgserver' instead of 'user@borgserver' ?
Exception: FD exception occurred
Probably running borg on cygwin, could be ssh key issue. Try
BORG_RSH="ssh -vvv" borg ...
Also check your quotes
Cache, or information obtained from the security directory is newer than repository - this is either an attack or unsafe (multiple repos with same ID)
Something broke during a backup, try (re)moving ~/.config/borg/security/<id> and ~/.cache/borg/<id>.
Prune: Chunk ID missing from chunks index, corrupted chunks index - aborting transaction.