It is not just about python3.6 but I can also see something similar with old kernel and python35 in latest rawhide userspace https://bugzilla.redhat.com/show_bug.cgi?id=1410187
BTW the explanation is that the latest update of glibc in rawhide provides functions getentropy and getrandom
objdump -T /lib64/libc.so.6 | grep GLIBC_2.25 000000000003c6f0 g DF .text 000000000000008c GLIBC_2.25 getentropy 0000000000000000 g DO *ABS* 0000000000000000 GLIBC_2.25 GLIBC_2.25 000000000003c9a0 g DF .text 000000000000020f GLIBC_2.25 strfromd 000000000003c780 g DF .text 000000000000021f GLIBC_2.25 strfromf 000000000003cbb0 g DF .text 000000000000021f GLIBC_2.25 strfroml 00000000000a3a60 g DF .text 0000000000000013 GLIBC_2.25 explicit_bzero 000000000011f1a0 g DF .text 0000000000000025 GLIBC_2.25 __explicit_bzero_chk 000000000003c650 g DF .text 0000000000000099 GLIBC_2.25 getrandom
and the latest python3 nad python35 packaeges uses it sh# rpm -q python3 python35 python3-3.6.0-1.fc26.x86_64 python35-3.5.2-5.fc26.x86_64
sh# objdump -T /usr/lib64/libpython3.5m.so | grep GLIBC_2.25 0000000000000000 DF *UND* 0000000000000000 GLIBC_2.25 getentropy
sh# objdump -T /usr/lib64/libpython3.6m.so | grep GLIBC_2.25 0000000000000000 DF *UND* 0000000000000000 GLIBC_2.25 getentropy
older version of python3 (3.5 at that time) didn't use it because it was compiled against older version of glibc
sh# objdump -T /usr/lib64/libpython3.so | grep GLIBC_2.25 sh# objdump -T /usr/lib64/libpython3.5m.so.1.0 | grep GLIBC_2.25 sh# rpm -q python3 python3-3.5.2-7.fc26.x86_64