Victor, where can you reproduce it (OS, python version, what C lib)?

I don't receive segfault, only sigpipe (see msg217818 ). Here's gdb backtrace after the signal:

Program received signal SIGPIPE, Broken pipe.
0x00007ffff71e1040 in __write_nocancel () at ../sysdeps/unix/syscall-template.S:82
82      ../sysdeps/unix/syscall-template.S: No such file or directory.
(gdb) backtrace
#0  0x00007ffff71e1040 in __write_nocancel () at ../sysdeps/unix/syscall-template.S:82
#1  0x00007ffff7173883 in _IO_new_file_write (f=0x7e1f10, data=0x7ffff66cb034,
    n=1097728) at fileops.c:1289
#2  0x00007ffff717374a in new_do_write (fp=0x7e1f10,
    data=0x7ffff66cb034 "0123456789\n...01"...,
    to_do=1097728) at fileops.c:543
#3  0x00007ffff71741fe in _IO_new_file_xsputn (n=1100000, data=<optimized out>,
    f=0x7e1f10) at fileops.c:1383
#4  _IO_new_file_xsputn (f=0x7e1f10, data=<optimized out>, n=1100000)
    at fileops.c:1305
#5  0x00007ffff7169cdd in _IO_fwrite (buf=<optimized out>, size=1, count=1100000,
    fp=0x7e1f10) at iofwrite.c:45
#6  0x000000000042c23c in file_write (f=0x7ffff7f16540, args=<optimized out>)
    at Objects/fileobject.c:1851

Note: the line is 1851, not 1852 (as in the latest 2.7 version [1]) as in your traceback.
And the calls inside _IO_new_file_xsputn() are also different.

[1]: http://hg.python.org/cpython/file/b768d41dec0a/Objects/fileobject.c#l1852

python2.7.6 is installed using `pythonz install 2.7.6` command.

Just to make sure that python2.7.6 *can* segfault:

  $ python2.7.6 -c'import ctypes; ctypes.memset(0,0,1)'
  Segmentation fault (core dumped)

core file is not written on my system:

  $ cat /proc/sys/kernel/core_pattern
  |/usr/share/apport/apport %p %s %c

But I can see in the log when a process segfaults e.g.,
the segfault due to memset is logged:

  $ tail -F /var/log/apport.log
  ERROR: apport (pid 8501) ... executable: ~/.pythonz/pythons/CPython-2.7.6/bin/python2.7 \
      (command line "python2.7.6 -cimport\ ctypes;\ ctypes.memset(0,0,1)")


To find out where `fwrite` come from, I've done:

  $ nm $(which python2.7.6) | grep fwrite
                   U fwrite@@GLIBC_2.2.5

  $ cat $(gcc -print-file-name=libc.so)
  /* GNU ld script
   ... */
  OUTPUT_FORMAT(elf64-x86-64)
  GROUP ( /lib/x86_64-linux-gnu/libc.so.6 ... )

  $ ldd $(which python2.7.6)
          ...
          libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6
          ...

  $ /lib/x86_64-linux-gnu/libc.so.6
  GNU C Library (Ubuntu EGLIBC 2.15-0ubuntu10.5) stable release version 2.15, by Roland McGrath et al.
  Copyright (C) 2012 Free Software Foundation, Inc.
  ...
  Compiled by GNU CC version 4.6.3.
  Compiled on a Linux 3.2.50 system on 2013-09-30.
  ...

/usr/bin/python behaves similar -- it just has version that is not mentioned by the OP.