The following test gives a segmentation fault on Fedora 18.
Program received signal SIGSEGV, Segmentation fault.
__memcpy_sse2 () at ../sysdeps/x86_64/memcpy.S:95
95 movl (%rsi), %ecx
(gdb) bt
#0 __memcpy_sse2 () at ../sysdeps/x86_64/memcpy.S:95
#1 0x00007ffff07dab9a in memcpy (__len=<optimized out>, __src=<optimized out>, __dest=0x6ce450) at /usr/include/bits/string3.h:51
#2 FS_func_write (obj=<optimized out>, args=<optimized out>, kwargs=<optimized out>) at src/fs.c:2247
#3 0x000000366bedd281 in call_function (oparg=<optimized out>, pp_stack=0x7fffffffdde8) at /usr/src/debug/Python-2.7.3/Python/ceval.c:4098
#4 PyEval_EvalFrameEx (f=f@entry=Frame 0x6cbe90, for file test.py, line 12, in <module> (), throwflag=throwflag@entry=0)
at /usr/src/debug/Python-2.7.3/Python/ceval.c:2740
#5 0x000000366beddcbf in PyEval_EvalCodeEx (co=co@entry=0x7ffff7f23a30, globals=globals@entry=
{'stat': <module at remote 0x7ffff7f7efa0>, 'TEST_FILE': 'test_file_1234', '__builtins__': <module at remote 0x7ffff7fa1ad0>, 'unittest2': <module at remote 0x7ffff7edb788>, '__file__': 'test.py', '__package__': None, 'fd': 14, 'pyuv': <module at remote 0x726fd8>, '__name__': '__main__', 'os': <module at remote 0x7ffff7f67cc8>, '__doc__': None, 'loop': <pyuv.Loop at remote 0x748578>}, locals=locals@entry=
{'stat': <module at remote 0x7ffff7f7efa0>, 'TEST_FILE': 'test_file_1234', '__builtins__': <module at remote 0x7ffff7fa1ad0>, 'unittest2': <module at remote 0x7ffff7edb788>, '__file__': 'test.py', '__package__': None, 'fd': 14, 'pyuv': <module at remote 0x726fd8>, '__name__': '__main__', 'os': <module at remote 0x7ffff7f67cc8>, '__doc__': None, 'loop': <pyuv.Loop at remote 0x748578>}, args=args@entry=0x0, argcount=argcount@entry=0,
kws=kws@entry=0x0, kwcount=kwcount@entry=0, defs=defs@entry=0x0, defcount=defcount@entry=0, closure=closure@entry=0x0)
at /usr/src/debug/Python-2.7.3/Python/ceval.c:3330
#6 0x000000366beddd92 in PyEval_EvalCode (co=co@entry=0x7ffff7f23a30, globals=globals@entry=
{'stat': <module at remote 0x7ffff7f7efa0>, 'TEST_FILE': 'test_file_1234', '__builtins__': <module at remote 0x7ffff7fa1ad0>, 'unittest2': <module at remote 0x7ffff7edb788>, '__file__': 'test.py', '__package__': None, 'fd': 14, 'pyuv': <module at remote 0x726fd8>, '__name__': '__main__', 'os': <module at remote 0x7ffff7f67cc8>, '__doc__': None, 'loop': <pyuv.Loop at remote 0x748578>}, locals=locals@entry=
{'stat': <module at remote 0x7ffff7f7efa0>, 'TEST_FILE': 'test_file_1234', '__builtins__': <module at remote 0x7ffff7fa1ad0>, 'unittest2': <module at remote 0x7ffff7edb788>, '__file__': 'test.py', '__package__': None, 'fd': 14, 'pyuv': <module at remote 0x726fd8>, '__name__': '__main__', 'os': <module at remote 0x7ffff7f67cc8>, '__doc__': None, 'loop': <pyuv.Loop at remote 0x748578>}) at /usr/src/debug/Python-2.7.3/Python/ceval.c:689
#7 0x000000366bef6f7a in run_mod (mod=<optimized out>, filename=filename@entry=0x7fffffffe52b "test.py", globals=globals@entry=
{'stat': <module at remote 0x7ffff7f7efa0>, 'TEST_FILE': 'test_file_1234', '__builtins__': <module at remote 0x7ffff7fa1ad0>, 'unittest2': <module at remote 0x7ffff7edb788>, '__file__': 'test.py', '__package__': None, 'fd': 14, 'pyuv': <module at remote 0x726fd8>, '__name__': '__main__', 'os': <module at remote 0x7ffff7f67cc8>, '__doc__': None, 'loop': <pyuv.Loop at remote 0x748578>}, locals=locals@entry=
{'stat': <module at remote 0x7ffff7f7efa0>, 'TEST_FILE': 'test_file_1234', '__builtins__': <module at remote 0x7ffff7fa1ad0>, 'unittest2': <module at remote 0x7ffff7edb788>, '__file__': 'test.py', '__package__': None, 'fd': 14, 'pyuv': <module at remote 0x726fd8>, '__name__': '__main__', 'os': <module at remote 0x7ffff7f67cc8>, '__doc__': None, 'loop': <pyuv.Loop at remote 0x748578>}, flags=flags@entry=0x7fffffffe060, arena=arena@entry=
0x6c8670) at /usr/src/debug/Python-2.7.3/Python/pythonrun.c:1361
#8 0x000000366bef7d72 in PyRun_FileExFlags (fp=fp@entry=0x6c8dc0, filename=filename@entry=0x7fffffffe52b "test.py", start=start@entry=257,
globals=globals@entry=
{'stat': <module at remote 0x7ffff7f7efa0>, 'TEST_FILE': 'test_file_1234', '__builtins__': <module at remote 0x7ffff7fa1ad0>, 'unittest2': <module at remote 0x7ffff7edb788>, '__file__': 'test.py', '__package__': None, 'fd': 14, 'pyuv': <module at remote 0x726fd8>, '__name__': '__main__', 'os': <module at remote 0x7ffff7f67cc8>, '__doc__': None, 'loop': <pyuv.Loop at remote 0x748578>}, locals=locals@entry=
{'stat': <module at remote 0x7ffff7f7efa0>, 'TEST_FILE': 'test_file_1234', '__builtins__': <module at remote 0x7ffff7fa1ad0>, 'unittest2': <module at remote 0x7ffff7edb788>, '__file__': 'test.py', '__package__': None, 'fd': 14, 'pyuv': <module at remote 0x726fd8>, '__name__': '__main__', 'os': <module at remote 0x7ffff7f67cc8>, '__doc__': None, 'loop': <pyuv.Loop at remote 0x748578>}, closeit=closeit@entry=1, flags=flags@entry=0x7fffffffe060)
at /usr/src/debug/Python-2.7.3/Python/pythonrun.c:1347
#9 0x000000366bef878b in PyRun_SimpleFileExFlags (fp=fp@entry=0x6c8dc0, filename=0x7fffffffe52b "test.py", closeit=1, flags=flags@entry=
---Type <return> to continue, or q <return> to quit---
0x7fffffffe060) at /usr/src/debug/Python-2.7.3/Python/pythonrun.c:951
#10 0x000000366bef93c9 in PyRun_AnyFileExFlags (fp=fp@entry=0x6c8dc0, filename=<optimized out>, closeit=<optimized out>, flags=flags@entry=
0x7fffffffe060) at /usr/src/debug/Python-2.7.3/Python/pythonrun.c:755
#11 0x000000366bf09c52 in Py_Main (argc=<optimized out>, argv=<optimized out>) at /usr/src/debug/Python-2.7.3/Modules/main.c:639
#12 0x0000003652a21a05 in __libc_start_main (main=0x4006f0 <main>, argc=2, ubp_av=0x7fffffffe218, init=<optimized out>, fini=<optimized out>,
rtld_fini=<optimized out>, stack_end=0x7fffffffe208) at libc-start.c:225
#13 0x0000000000400721 in _start ()