segmentation fault: 12 qubit master equation

[markus-grassl]

Hello,

I am trying to help a colleague debugging his python program. He has a 12 qubit master equation.
Pretty early after calling 'qutip.mesolve', a segmentation fault occurs.
Using gdb, I found that the crash occurs in

Program received signal SIGSEGV, Segmentation fault.
__pyx_f_5qutip_2cy_6spmath_free_CSR (__pyx_v_mat=0x7fffffffc380) at qutip/cy/spmath.cpp:4592
4592 qutip/cy/spmath.cpp: No such file or directory.

A backtrace (from a different run) is included below. There is the line

#2 0x00007fffe225d20c in __pyx_f_5qutip_2cy_6spmath_init_CSR (__pyx_v_mat=0x7fffffffb2a0, __pyx_v_nnz=-1879048192, __pyx_v_nrows=16777216, __pyx_optional_args=) at qutip/cy/spmath.cpp:3947

which has a negative value for pyx_v_nnz, which hints at an integer overflow that was not caught while checking parameters; but I don't have the source code, so this is mere guessing.

We have qutip V4.7.3 installed.

Any hints?

Thanks

Markus

Program received signal SIGSEGV, Segmentation fault.
_pyx_f_5_qutip_2cy_6spmath_free_CSR (__pyx_v_mat=0x7fffffffb2a0) at qutip/cy/spmath.cpp:4592
4592 qutip/cy/spmath.cpp: No such file or directory.
(gdb) backtrace
#0 __pyx_f_5qutip_2cy_6spmath_free_CSR (__pyx_v_mat=0x7fffffffb2a0) at qutip/cy/spmath.cpp:4592
#1 0x00007fffe225cee9 in __pyx_f_5qutip_2cy_6spmath_raise_error_CSR (__pyx_v_E=-1, __pyx_optional_args=) at qutip/cy/spmath.cpp:3248
#2 0x00007fffe225d20c in __pyx_f_5qutip_2cy_6spmath_init_CSR (__pyx_v_mat=0x7fffffffb2a0, __pyx_v_nnz=-1879048192, __pyx_v_nrows=16777216,
__pyx_optional_args=) at qutip/cy/spmath.cpp:3947
#3 0x00007fffe22852c5 in __pyx_pf_5qutip_2cy_6spmath_2zcsr_mult (__pyx_v_A=, __pyx_v_B=, __pyx_v_sorted=1,
__pyx_self=) at qutip/cy/spmath.cpp:10017
#4 0x00007ffff7d79752 in cfunction_call () from /lib64/libpython3.9.so.1.0
#5 0x00007ffff7d6b76c in _PyObject_MakeTpCall () from /lib64/libpython3.9.so.1.0
#6 0x00007ffff7d6881b in _PyEval_EvalFrameDefault () from /lib64/libpython3.9.so.1.0
#7 0x00007ffff7d6fe03 in function_code_fastcall () from /lib64/libpython3.9.so.1.0
#8 0x00007ffff7d635f3 in _PyEval_EvalFrameDefault () from /lib64/libpython3.9.so.1.0
#9 0x00007ffff7d6fe03 in function_code_fastcall () from /lib64/libpython3.9.so.1.0
#10 0x00007ffff7d635f3 in _PyEval_EvalFrameDefault () from /lib64/libpython3.9.so.1.0
#11 0x00007ffff7d6fe03 in function_code_fastcall () from /lib64/libpython3.9.so.1.0
#12 0x00007ffff7dbd54b in vectorcall_maybe.constprop () from /lib64/libpython3.9.so.1.0
#13 0x00007ffff7e35f9b in slot_nb_multiply () from /lib64/libpython3.9.so.1.0
#14 0x00007ffff7d7a330 in binary_op1 () from /lib64/libpython3.9.so.1.0
#15 0x00007ffff7d63f49 in _PyEval_EvalFrameDefault () from /lib64/libpython3.9.so.1.0
#16 0x00007ffff7d61ee5 in _PyEval_EvalCode () from /lib64/libpython3.9.so.1.0
#17 0x00007ffff7d6fb75 in _PyFunction_Vectorcall () from /lib64/libpython3.9.so.1.0
#18 0x00007ffff7dbd54b in vectorcall_maybe.constprop () from /lib64/libpython3.9.so.1.0
#19 0x00007ffff7e35f9b in slot_nb_multiply () from /lib64/libpython3.9.so.1.0
#20 0x00007ffff7d7a330 in binary_op1 () from /lib64/libpython3.9.so.1.0
#21 0x00007ffff7e2f671 in PyNumber_InPlaceMultiply () from /lib64/libpython3.9.so.1.0
#22 0x00007ffff7d65fd2 in _PyEval_EvalFrameDefault () from /lib64/libpython3.9.so.1.0
#23 0x00007ffff7d6fe03 in function_code_fastcall () from /lib64/libpython3.9.so.1.0
#24 0x00007ffff7da3843 in vectorcall_method () from /lib64/libpython3.9.so.1.0
#25 0x00007ffff7e5a65c in slot_nb_inplace_multiply () from /lib64/libpython3.9.so.1.0
#26 0x00007ffff7de1f3f in binary_iop1 () from /lib64/libpython3.9.so.1.0
#27 0x00007ffff7e2f671 in PyNumber_InPlaceMultiply () from /lib64/libpython3.9.so.1.0
#28 0x00007ffff7d65fd2 in _PyEval_EvalFrameDefault () from /lib64/libpython3.9.so.1.0
#29 0x00007ffff7d6fe03 in function_code_fastcall () from /lib64/libpython3.9.so.1.0
#30 0x00007ffff7dbd54b in vectorcall_maybe.constprop () from /lib64/libpython3.9.so.1.0
#31 0x00007ffff7e35f9b in slot_nb_multiply () from /lib64/libpython3.9.so.1.0
#32 0x00007ffff7d7a330 in binary_op1 () from /lib64/libpython3.9.so.1.0
#33 0x00007ffff7d63f49 in _PyEval_EvalFrameDefault () from /lib64/libpython3.9.so.1.0
#34 0x00007ffff7d61ee5 in _PyEval_EvalCode () from /lib64/libpython3.9.so.1.0
#35 0x00007ffff7d6fb75 in _PyFunction_Vectorcall () from /lib64/libpython3.9.so.1.0
#36 0x00007ffff7d6331d in _PyEval_EvalFrameDefault () from /lib64/libpython3.9.so.1.0
#37 0x00007ffff7d6fe03 in function_code_fastcall () from /lib64/libpython3.9.so.1.0
#38 0x00007ffff7d6331d in _PyEval_EvalFrameDefault () from /lib64/libpython3.9.so.1.0
#39 0x00007ffff7d61ee5 in _PyEval_EvalCode () from /lib64/libpython3.9.so.1.0
#40 0x00007ffff7d6fb75 in _PyFunction_Vectorcall () from /lib64/libpython3.9.so.1.0
#41 0x00007ffff7d642d6 in _PyEval_EvalFrameDefault () from /lib64/libpython3.9.so.1.0
#42 0x00007ffff7d61ee5 in _PyEval_EvalCode () from /lib64/libpython3.9.so.1.0
#43 0x00007ffff7ddc965 in _PyEval_EvalCodeWithName () from /lib64/libpython3.9.so.1.0
#44 0x00007ffff7ddc8fd in PyEval_EvalCodeEx () from /lib64/libpython3.9.so.1.0
#45 0x00007ffff7ddc8af in PyEval_EvalCode () from /lib64/libpython3.9.so.1.0
#46 0x00007ffff7de2363 in builtin_exec () from /lib64/libpython3.9.so.1.0
#47 0x00007ffff7d700e0 in cfunction_vectorcall_FASTCALL () from /lib64/libpython3.9.so.1.0
#48 0x00007ffff7d6ac26 in _PyObject_VectorcallTstate.lto_priv.5 () from /lib64/libpython3.9.so.1.0
#49 0x00007ffff7cbae33 in _PyEval_EvalFrameDefault.cold () from /lib64/libpython3.9.so.1.0
#50 0x00007ffff7d61ee5 in _PyEval_EvalCode () from /lib64/libpython3.9.so.1.0
#51 0x00007ffff7ddc965 in _PyEval_EvalCodeWithName () from /lib64/libpython3.9.so.1.0
#52 0x00007ffff7ddc8fd in PyEval_EvalCodeEx () from /lib64/libpython3.9.so.1.0
#53 0x00007ffff7ddc8af in PyEval_EvalCode () from /lib64/libpython3.9.so.1.0
#54 0x00007ffff7de2363 in builtin_exec () from /lib64/libpython3.9.so.1.0
#55 0x00007ffff7d700e0 in cfunction_vectorcall_FASTCALL () from /lib64/libpython3.9.so.1.0
#56 0x00007ffff7d6ac26 in _PyObject_VectorcallTstate.lto_priv.5 () from /lib64/libpython3.9.so.1.0
#57 0x00007ffff7cbae33 in _PyEval_EvalFrameDefault.cold () from /lib64/libpython3.9.so.1.0
#58 0x00007ffff7d61ee5 in _PyEval_EvalCode () from /lib64/libpython3.9.so.1.0
#59 0x00007ffff7d6fb75 in _PyFunction_Vectorcall () from /lib64/libpython3.9.so.1.0
#60 0x00007ffff7d635f3 in _PyEval_EvalFrameDefault () from /lib64/libpython3.9.so.1.0
#61 0x00007ffff7d6fe03 in function_code_fastcall () from /lib64/libpython3.9.so.1.0
#62 0x00007ffff7d635f3 in _PyEval_EvalFrameDefault () from /lib64/libpython3.9.so.1.0
#63 0x00007ffff7d6fe03 in function_code_fastcall () from /lib64/libpython3.9.so.1.0
#64 0x00007ffff7d67fa5 in _PyEval_EvalFrameDefault () from /lib64/libpython3.9.so.1.0
#65 0x00007ffff7d61ee5 in _PyEval_EvalCode () from /lib64/libpython3.9.so.1.0
#66 0x00007ffff7ddc965 in _PyEval_EvalCodeWithName () from /lib64/libpython3.9.so.1.0
#67 0x00007ffff7ddc8fd in PyEval_EvalCodeEx () from /lib64/libpython3.9.so.1.0
#68 0x00007ffff7ddc8af in PyEval_EvalCode () from /lib64/libpython3.9.so.1.0
#69 0x00007ffff7de2363 in builtin_exec () from /lib64/libpython3.9.so.1.0
#70 0x00007ffff7d700e0 in cfunction_vectorcall_FASTCALL () from /lib64/libpython3.9.so.1.0
#71 0x00007ffff7d6331d in _PyEval_EvalFrameDefault () from /lib64/libpython3.9.so.1.0
#72 0x00007ffff7d61ee5 in _PyEval_EvalCode () from /lib64/libpython3.9.so.1.0
#73 0x00007ffff7d6fb75 in _PyFunction_Vectorcall () from /lib64/libpython3.9.so.1.0
#74 0x00007ffff7d6331d in _PyEval_EvalFrameDefault () from /lib64/libpython3.9.so.1.0
#75 0x00007ffff7d61ee5 in _PyEval_EvalCode () from /lib64/libpython3.9.so.1.0
#76 0x00007ffff7d6fb75 in _PyFunction_Vectorcall () from /lib64/libpython3.9.so.1.0
#77 0x00007ffff7dff0e9 in pymain_run_module () from /lib64/libpython3.9.so.1.0
#78 0x00007ffff7dfeb27 in Py_RunMain () from /lib64/libpython3.9.so.1.0
#79 0x00007ffff7dcf2bd in Py_BytesMain () from /lib64/libpython3.9.so.1.0
#80 0x00007ffff7a89eb0 in __libc_start_call_main () from /lib64/libc.so.6
#81 0x00007ffff7a89f60 in __libc_start_main_impl () from /lib64/libc.so.6
#82 0x0000555555555095 in _start ()