_sys___select50() triggering lots of SIGTRAPS in gdb?

[bch%methodlogic.net@localhost]

I'm trying to run tclsh under gdb (session transcript below). Why are
all the SIGTRAPS being issued? I googled then, and got a Debian mailing
list where it's suggested it's a kernel bug, and certainly -not- gdb
(http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=475206). Any insight
for this case?

kamloops$ uname -a
NetBSD kamloops 5.99.48 NetBSD 5.99.48 (kamloops) #21: Tue Apr  5 09:04:12 PDT 
2011  root@kamloops:/usr/obj/sys/arch/amd64/compile/kamloops amd64
kamloops$ gdb tclsh8.6
GNU gdb 6.5
Copyright (C) 2006 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License
welcome to change it and/or distribute copies of it under certa
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB.  Type "show warranty" 
This GDB was configured as "x86_64--netbsd"...
(gdb) run
Starting program: /usr/pkg/bin/tclsh8.6 

Program received signal SIGTRAP, Trace/breakpoint trap.
0x00007f7ff68380fa in _sys___select50 () from /usr/lib/libc.so.
(gdb) cont
Continuing.

Program received signal SIGTRAP, Trace/breakpoint trap.
0x00007f7ff68380fa in _sys___select50 () from /usr/lib/libc.so.
(gdb) 
Continuing.

Program received signal SIGTRAP, Trace/breakpoint trap.
0x00007f7ff68380fa in _sys___select50 () from /usr/lib/libc.so.
(gdb) 
Continuing.

Program received signal SIGTRAP, Trace/breakpoint trap.
0x00007f7ff68380fa in _sys___select50 () from /usr/lib/libc.so.
(gdb) 
Continuing.
% puts "finally at tclsh prompt"
finally at tclsh prompt
%

-- 
Brad Harder
Method Logic Digital Consulting
http://methodlogic.net/
http://twitter.com/bcharder