*** Break *** segmentation violation =========================================================== There was a crash. This is the entire stack trace of all threads: =========================================================== Thread 2 (Thread 0x7faf7cd6e700 (LWP 29225)): #0 0x00000037d820d930 in sem_wait () from /lib64/libpthread.so.0 #1 0x00007faf9b01d55d in PyThread_acquire_lock (lock=0x9ad130, waitflag=1) at Python/thread_pthread.h:323 #2 0x00007faf9afe1b34 in PyEval_RestoreThread (tstate=0x2cf71b0) at Python/ceval.c:357 #3 0x00007faf7dd55505 in floatsleep (self=, args=) at /home3/candles/local/python/Python-2.7.5/Modules/timemodule.c:959 #4 time_sleep (self=, args=) at /home3/candles/local/python/Python-2.7.5/Modules/timemodule.c:206 #5 0x00007faf9afe81a9 in call_function (f=0x7faf78000ef0, throwflag=) at Python/ceval.c:4021 #6 PyEval_EvalFrameEx (f=0x7faf78000ef0, throwflag=) at Python/ceval.c:2666 #7 0x00007faf9afe9ab9 in PyEval_EvalCodeEx (co=0x7faf9a9e01b0, globals=, locals=, args=0x2a172e8, argcount=1, kws=0x7faf9aeba068, kwcount=0, defs=0x0, defcount=0, closure=0x0) at Python/ceval.c:3253 #8 0x00007faf9af6e9b2 in function_call (func=0x2219668, arg=0x2a172d0, kw=0x2d07d10) at Objects/funcobject.c:526 #9 0x00007faf9af40a98 in PyObject_Call (func=0x2219668, arg=0x2a172d0, kw=0x2d07d10) at Objects/abstract.c:2529 #10 0x00007faf9afe5435 in ext_do_call (f=0x7faf78000d20, throwflag=) at Python/ceval.c:4334 #11 PyEval_EvalFrameEx (f=0x7faf78000d20, throwflag=) at Python/ceval.c:2705 #12 0x00007faf9afe8cf8 in call_function (f=0x7faf78000ae0, throwflag=) at Python/ceval.c:4107 #13 PyEval_EvalFrameEx (f=0x7faf78000ae0, throwflag=) at Python/ceval.c:2666 #14 0x00007faf9afe8cf8 in call_function (f=0x7faf78000910, throwflag=) at Python/ceval.c:4107 #15 PyEval_EvalFrameEx (f=0x7faf78000910, throwflag=) at Python/ceval.c:2666 #16 0x00007faf9afe9ab9 in PyEval_EvalCodeEx (co=0x2a12330, globals=, locals=, args=0x2a172a8, argcount=1, kws=0x0, kwcount=0, defs=0x0, defcount=0, closure=0x0) at Python/ceval.c:3253 #17 0x00007faf9af6e9b2 in function_call (func=0x2a1ce60, arg=0x2a17290, kw=0x0) at Objects/funcobject.c:526 #18 0x00007faf9af40a98 in PyObject_Call (func=0x2a1ce60, arg=0x2a17290, kw=0x0) at Objects/abstract.c:2529 #19 0x00007faf9af5116f in instancemethod_call (func=, arg=0x2a17290, kw=0x0) at Objects/classobject.c:2602 #20 0x00007faf9af40a98 in PyObject_Call (func=0x29a8eb0, arg=0x7faf9aeba050, kw=0x0) at Objects/abstract.c:2529 #21 0x00007faf9afe1046 in PyEval_CallObjectWithKeywords (func=0x29a8eb0, arg=0x7faf9aeba050, kw=0x0) at Python/ceval.c:3890 #22 0x00007faf9b021a12 in t_bootstrap (boot_raw=0x2d0d7a0) at ./Modules/threadmodule.c:614 #23 0x00000037d82079d1 in start_thread () from /lib64/libpthread.so.0 #24 0x00000037d7ee886d in clone () from /lib64/libc.so.6 Thread 1 (Thread 0x7faf9ae9b700 (LWP 28972)): #0 0x00000037d7eac61d in waitpid () from /lib64/libc.so.6 #1 0x00000037d7e3e619 in do_system () from /lib64/libc.so.6 #2 0x00000037d7e3e950 in system () from /lib64/libc.so.6 #3 0x00007faf94387f2a in TUnixSystem::StackTrace() () from /home/candles/local/root/6.08.00/lib/root/libCore.so #4 0x00007faf9438a62c in TUnixSystem::DispatchSignals(ESignals) () from /home/candles/local/root/6.08.00/lib/root/libCore.so #5 #6 0x0000000003bfcb70 in ?? () #7 0x00007faf7738b46d in TF1::EvalPar(double const*, double const*) () from /home/candles/local/root/6.08.00/lib/root/libHist.so #8 0x00007faf7739bcac in TF1_EvalWrapper::DoEval(double) const () from /home/candles/local/root/6.08.00/lib/root/libHist.so #9 0x000000387f08e339 in gsl_integration_qk () from /usr/lib64/libgsl.so.0 #10 0x000000387f08e11b in gsl_integration_qk21 () from /usr/lib64/libgsl.so.0 #11 0x000000387f08fe10 in ?? () from /usr/lib64/libgsl.so.0 #12 0x00007faf7653c967 in ROOT::Math::GSLIntegrator::Integral(double, double) () from /home/candles/local/root/6.08.00/lib/root/libMathMore.so #13 0x00007faf7739a3a7 in TF1::IntegralOneDim(double, double, double, double, double&) () from /home/candles/local/root/6.08.00/lib/root/libHist.so #14 0x00007faf7738cb71 in TF1::Integral(double, double, double) () from /home/candles/local/root/6.08.00/lib/root/libHist.so #15 0x00007faf94a1106b in ?? () #16 0x0000000000000000 in ?? () =========================================================== The lines below might hint at the cause of the crash. You may get help by asking at the ROOT forum http://root.cern.ch/forum. Only if you are really convinced it is a bug in ROOT then please submit a report at http://root.cern.ch/bugs. Please post the ENTIRE stack trace from above as an attachment in addition to anything else that might help us fixing this issue. =========================================================== #6 0x0000000003bfcb70 in ?? () #7 0x00007faf7738b46d in TF1::EvalPar(double const*, double const*) () from /home/candles/local/root/6.08.00/lib/root/libHist.so #8 0x00007faf7739bcac in TF1_EvalWrapper::DoEval(double) const () from /home/candles/local/root/6.08.00/lib/root/libHist.so #9 0x000000387f08e339 in gsl_integration_qk () from /usr/lib64/libgsl.so.0 #10 0x000000387f08e11b in gsl_integration_qk21 () from /usr/lib64/libgsl.so.0 #11 0x000000387f08fe10 in ?? () from /usr/lib64/libgsl.so.0 #12 0x00007faf7653c967 in ROOT::Math::GSLIntegrator::Integral(double, double) () from /home/candles/local/root/6.08.00/lib/root/libMathMore.so #13 0x00007faf7739a3a7 in TF1::IntegralOneDim(double, double, double, double, double&) () from /home/candles/local/root/6.08.00/lib/root/libHist.so #14 0x00007faf7738cb71 in TF1::Integral(double, double, double) () from /home/candles/local/root/6.08.00/lib/root/libHist.so #15 0x00007faf94a1106b in ?? () #16 0x0000000000000000 in ?? () =========================================================== Traceback (most recent call last): File "PoissMinuitFitv2.py", line 757, in Integral = ffree.Integral(0, 0.003) SystemError: double TF1::Integral(double a, double b, double epsrel = 9.9999999999999998E-13) => problem in C++; program state has been reset