$ LD_PRELOAD=libsiginfo.so.0  python -c "import time; time.sleep(5)"
^T
load: 0.63  cmd: python3.6 69132 [select] 2.02r 0.01u 0.00s 0% 10180k
#0 0xffffffff80bd04f3 at mi_switch+0xd3
#1 0xffffffff80c2278e at sleepq_catch_signals+0x39e
#2 0xffffffff80c23592 at sleepq_timedwait_sig+0x12
#3 0xffffffff80b58f6e at _cv_timedwait_sig_sbt+0xee
#4 0xffffffff80c3307f at seltdwait+0xff
#5 0xffffffff80c33c96 at kern_select.part.10+0x556
#6 0xffffffff80c355e5 at sys_select+0x65
#7 0xffffffff8119e290 at amd64_syscall+0x2b0
#8 0xffffffff81176690 at fast_syscall_common+0x101
-------------------- userspace --------------------
#0  0x0008007740fa at /lib/libc.so.7:__sys_select+0xa
#1  0x0008002594b2 at /lib/libthr.so.3:_pthread_suspend_all_np+0x1632
#2  0x0008004b3ffc at /usr/local/lib/libpython3.6m.so.1.0:PyInit_time+0x61c
#3  0x0008003bca36 at /usr/local/lib/libpython3.6m.so.1.0:_PyCFunction_FastCallDict+0x246
#4  0x00080043d355 at /usr/local/lib/libpython3.6m.so.1.0:PyEval_GetFuncDesc+0x225
#5  0x00080043a9f1 at /usr/local/lib/libpython3.6m.so.1.0:_PyEval_EvalFrameDefault+0x61e1
#6  0x00080043dbf0 at /usr/local/lib/libpython3.6m.so.1.0:PyEval_GetFuncDesc+0xac0
#7  0x000800434763 at /usr/local/lib/libpython3.6m.so.1.0:PyEval_EvalCode+0x33
#8  0x000800468d2d at /usr/local/lib/libpython3.6m.so.1.0:PyRun_StringFlags+0x8d
#9  0x000800468c65 at /usr/local/lib/libpython3.6m.so.1.0:PyRun_SimpleStringFlags+0x45
#10 0x0008004835b1 at /usr/local/lib/libpython3.6m.so.1.0:Py_Main+0xa41
#11 0x0000002013c8 at /usr/local/bin/python:main+0xf8
#12 0x00000020110f at /usr/local/bin/python:_start+0x10f