The signal handling in svnadmin, svnlook and the cmdline client is lacking. The result is that it's way too easy to make a respository hang which makes Subversion seem fragile. All you need to do is to press ctrl-c during a dump or verify, or use "svnlook cat | more" and quit more by pressing q. The (soon to be) attached patch addresses this by implementing cancellation support to the dump/load/verify code, by handling SIGINT, SIGHUP and SIGTERM, and by ignoring SIGPIPE. The cmdline client already has SIGINT handling.
Original issue reported by bliss