Transmission: how to debug seccomp?

On my system, transmission crashes a lot. One of the crashes, the only one I can reproduce reliably, happens when a downloaded torrent is finalized and is moved from the temporary download dir to the finished dir. If the finished dir is a nfs mount point, transmission crashes every time.

I suspect that seccomp is too restrictive. How do I investigate this? There is nothing in the syslog and nothing in the transmission log. Is there a separate log for seccomp? How do I enable it?