I am running this setup: $ svn --version svn, Version 1.6.16 (r1073529) übersetzt Apr 26 2011, 12:14:40 $ uname -a FreeBSD blnn719x.ww004.siemens.net 8.2-STABLE FreeBSD 8.2-STABLE #11: Thu Apr 21 23:33:30 CEST 2011 root@obfucated i386 I am behind an ISA proxy with requires to authenticate through Negotiate auth scheme. I have subversion configured to use this proxy. running kinit to obtain a kerberos tgt and running some svn command makes neon to fetch a service ticket HTTP/proxy server. This works perfectly even with cross-realm. If the tgt has expired: $ klist Credentials cache: FILE:/tmp/krb5cc_722 Principal: princ@realm Issued Expires Principal May 3 10:01:46 >>>Expired<<< krbtgt/realm@realm a svn command quits with: $ svn up Segmentation fault: 11 (Speicherabzug geschrieben) A core dump has been written too. This can be attached if necessary. If neon fails to obtain a ticket subversion should exit with an appropriate error message instead of a segmentation fault.