cvs dumps core (AMD64)

On AMD64/edgy, cvs seems to consistently dump core on my machine. Version of CVS package:

% dpkg -l cvs | grep cvs
ii cvs 1.12.13-3 Concurrent Versions System

The CVSROOT is valid, and the same repository worked fine with Dapper:

% ls $CVSROOT
CVSROOT interfaces pgsql sup

But most CVS operations on existing or new checkouts from this repository result in a core dump. Unfortunately, the back trace isn't much help without debugging symbols: (I can rebuild w/ them if needed.)

% gdb --quiet cvs
(gdb) set args co -d /tmp/x pgsql
(gdb) r
Starting program: /usr/bin/cvs co -d /tmp/x pgsql
(no debugging symbols found)
[...]
[Thread debugging using libthread_db enabled]
[New Thread 47250665700064 (LWP 7537)]
(no debugging symbols found)
[...]
Program received signal SIGSEGV, Segmentation fault.
(gdb) bt
#0 0x00000000004350a7 in error ()
#1 0x000000000042dd40 in error ()
#2 0x000000000042ed55 in error ()
#3 0x00002af966e110c4 in __libc_start_main () from /lib/libc.so.6
#4 0x0000000000404f19 in ?? ()
#5 0x00007fff44342c28 in ?? ()
#6 0x0000000000000000 in ?? ()

"cvs -t" displays the following:

% cvs -t -t co -d /tmp/x pgsql
  -> main: Session ID is b5uHAIr1lEsmfqQr
  -> Name_Root ((null), (null))
  -> parse_cvsroot (/home/neilc/postgres/cvs_root)
  -> walklist ( list=0x5b6b20, proc=0x42dbc0, closure=(nil) )
  -> main loop with CVSROOT=/home/neilc/postgres/cvs_root
  -> parse_config (/home/neilc/postgres/cvs_root)
  -> new_config ()

Trying to run "cvs up" on an existing checkout core dumps in the same way, with the same "-t" output as above.

The new_config() call above suggests that the problem might be caused by a malformed .cvsrc file or the like, but I moved that file out of the way and it didn't change this behavior.

Building the vanilla 1.12.3 upstream release from source yields a fully functional cvs binary that doesn't exhibit these problems.