unison freezes entire machine

[geezel@…]

Running unison on a single folder with only a few (about 50) large files freezes the entire machine. Unison itself does not crash or display an error message, but it consumes more and more memory until the machine reboots. Other processes also become unresponsive, i.e. once the unison command is launched there is no way to recover.

For reasons discussed in this ticket ticket:45621 this has been tested with various versions (unison 2.40.102 compiled against ocaml 4.01 and 4.02, and unison 2.48.3 against ocaml 4.01). They all exhibit the same behaviour.

Unison on FreeBSD runs fine on the same set of files (all versions). Also, a temporary workaround on Mac OS X is to run unison with the option "copythreshold = 1024", which makes unison use rsync to transfer large files.

This might well be an upstream bug. If anybody is able to confirm this behaviour I'd be willing to report it upstream.