Here are the last 10 frames from the backtrace (gdb):
#0 0x00000000005b15d0 in odictiter_iternext (di=<optimized out>) at Objects/odictobject.c:1888
#1 0x0000000000453179 in PyIter_Next (iter=<optimized out>) at Objects/abstract.c:2760
#2 0x00000000005881e7 in chain_next (lz=0x7ffff2b8d878) at ./Modules/itertoolsmodule.c:1866
#3 0x0000000000537db6 in PyEval_EvalFrameEx (f=f@entry=0xcab188, throwflag=throwflag@entry=0) at Python/ceval.c:2975
#4 0x000000000053afee in fast_function (func=func@entry=0x7ffff2bc88f8, pp_stack=pp_stack@entry=0x7fffffff99f8, n=n@entry=1, na=na@entry=1, nk=nk@entry=0) at Python/ceval.c:4752
#5 0x000000000053b655 in call_function (pp_stack=pp_stack@entry=0x7fffffff99f8, oparg=oparg@entry=0) at Python/ceval.c:4679
#6 0x000000000053891d in PyEval_EvalFrameEx (f=f@entry=0xcbd588, throwflag=throwflag@entry=0) at Python/ceval.c:3198
#7 0x000000000053afee in fast_function (func=func@entry=0x7ffff2bc8840, pp_stack=pp_stack@entry=0x7fffffff9bd8, n=n@entry=3, na=na@entry=3, nk=nk@entry=0) at Python/ceval.c:4752
#8 0x000000000053b655 in call_function (pp_stack=pp_stack@entry=0x7fffffff9bd8, oparg=oparg@entry=2) at Python/ceval.c:4679
#9 0x000000000053891d in PyEval_EvalFrameEx (f=f@entry=0xc7d458, throwflag=throwflag@entry=0) at Python/ceval.c:3198
and from Python:
Current thread 0x00007f3ad9260740 (most recent call first):
File "/home/esnow/projects/cordereddict/Lib/configparser.py", line 1115 in _join_multiline_values
File "/home/esnow/projects/cordereddict/Lib/configparser.py", line 1109 in _read
File "/home/esnow/projects/cordereddict/Lib/configparser.py", line 716 in read_file
File "/home/esnow/projects/cordereddict/Lib/configparser.py", line 721 in read_string
File "/home/esnow/projects/cordereddict/Lib/test/test_configparser.py", line 354 in test_basic
File "/home/esnow/projects/cordereddict/Lib/unittest/case.py", line 597 in run