"corrupted double-linked list" when running poller-wrapper.py

When running poller-wrapper.py, after LibreNMS has finished polling all devices, the Python script errors out with corrupted double-linked list as can be seen below. Before I start spending valuable time on debugging this, I am wondering if someone else has seen the same behaviour, and if someone perhaps knows about a solution.

root@librenms0:/opt/librenms# /opt/librenms/poller-wrapper.py
INFO: starting the poller at 2020-03-23 17:13:34 with 16 threads, slowest devices first
INFO: worker Thread-10 finished device 138 in 2 seconds
INFO: worker Thread-14 finished device 99 in 2 seconds
INFO: worker Thread-15 finished device 109 in 3 seconds
INFO: worker Thread-16 finished device 242 in 3 seconds
INFO: worker Thread-13 finished device 205 in 3 seconds
INFO: worker Thread-8 finished device 108 in 3 seconds
INFO: worker Thread-12 finished device 172 in 3 seconds
INFO: worker Thread-6 finished device 98 in 3 seconds
INFO: worker Thread-7 finished device 97 in 3 seconds
INFO: worker Thread-5 finished device 173 in 4 seconds
INFO: worker Thread-11 finished device 150 in 4 seconds
INFO: worker Thread-10 finished device 231 in 2 seconds
INFO: worker Thread-13 finished device 91 in 2 seconds
INFO: worker Thread-15 finished device 65 in 2 seconds
INFO: worker Thread-7 finished device 100 in 2 seconds
INFO: worker Thread-6 finished device 103 in 2 seconds
INFO: worker Thread-12 finished device 199 in 2 seconds
INFO: worker Thread-5 finished device 208 in 2 seconds
INFO: worker Thread-11 finished device 92 in 2 seconds
INFO: worker Thread-8 finished device 32 in 3 seconds
INFO: worker Thread-13 finished device 101 in 2 seconds
INFO: worker Thread-12 finished device 236 in 2 seconds
INFO: worker Thread-6 finished device 104 in 2 seconds
INFO: worker Thread-7 finished device 102 in 2 seconds
INFO: worker Thread-5 finished device 198 in 2 seconds
INFO: worker Thread-11 finished device 214 in 2 seconds
INFO: worker Thread-8 finished device 204 in 2 seconds
INFO: worker Thread-10 finished device 57 in 2 seconds
INFO: worker Thread-12 finished device 251 in 1 seconds
INFO: worker Thread-15 finished device 123 in 2 seconds
INFO: worker Thread-1 finished device 69 in 10 seconds
INFO: worker Thread-11 finished device 233 in 1 seconds
INFO: worker Thread-5 finished device 117 in 2 seconds
INFO: worker Thread-8 finished device 120 in 1 seconds
INFO: worker Thread-10 finished device 180 in 1 seconds
INFO: worker Thread-15 finished device 249 in 1 seconds
INFO: worker Thread-12 finished device 133 in 2 seconds
INFO: worker Thread-1 finished device 125 in 2 seconds
INFO: worker Thread-13 finished device 141 in 2 seconds
INFO: worker Thread-6 finished device 122 in 2 seconds
INFO: worker Thread-5 finished device 166 in 2 seconds
INFO: worker Thread-11 finished device 137 in 2 seconds
INFO: worker Thread-7 finished device 159 in 2 seconds
INFO: worker Thread-8 finished device 119 in 2 seconds
INFO: worker Thread-4 finished device 3 in 13 seconds
INFO: worker Thread-10 finished device 186 in 2 seconds
INFO: worker Thread-15 finished device 105 in 1 seconds
INFO: worker Thread-12 finished device 171 in 2 seconds
INFO: worker Thread-1 finished device 111 in 1 seconds
INFO: worker Thread-13 finished device 234 in 2 seconds
INFO: worker Thread-5 finished device 48 in 2 seconds
INFO: worker Thread-6 finished device 46 in 2 seconds
INFO: worker Thread-11 finished device 118 in 2 seconds
INFO: worker Thread-7 finished device 239 in 2 seconds
INFO: worker Thread-8 finished device 178 in 2 seconds
INFO: worker Thread-3 finished device 240 in 2 seconds
INFO: worker Thread-4 finished device 235 in 2 seconds
INFO: worker Thread-2 finished device 140 in 2 seconds
INFO: worker Thread-10 finished device 170 in 2 seconds
INFO: worker Thread-9 finished device 219 in 2 seconds
INFO: worker Thread-15 finished device 179 in 2 seconds
INFO: worker Thread-12 finished device 230 in 1 seconds
INFO: worker Thread-1 finished device 228 in 2 seconds
INFO: worker Thread-13 finished device 158 in 2 seconds
INFO: worker Thread-6 finished device 246 in 2 seconds
INFO: worker Thread-5 finished device 225 in 2 seconds
INFO: worker Thread-8 finished device 55 in 2 seconds
INFO: worker Thread-7 finished device 216 in 2 seconds
INFO: worker Thread-11 finished device 241 in 2 seconds
INFO: worker Thread-4 finished device 54 in 2 seconds
INFO: worker Thread-10 finished device 224 in 2 seconds
INFO: worker Thread-2 finished device 191 in 2 seconds
INFO: worker Thread-3 finished device 217 in 2 seconds
INFO: worker Thread-9 finished device 238 in 2 seconds
INFO: worker Thread-14 finished device 188 in 2 seconds
INFO: worker Thread-15 finished device 33 in 2 seconds
INFO: worker Thread-12 finished device 185 in 1 seconds
INFO: worker Thread-1 finished device 63 in 1 seconds
INFO: worker Thread-16 finished device 227 in 1 seconds
INFO: worker Thread-13 finished device 244 in 1 seconds
INFO: worker Thread-6 finished device 168 in 1 seconds
INFO: worker Thread-5 finished device 190 in 1 seconds
INFO: worker Thread-8 finished device 247 in 1 seconds
INFO: worker Thread-7 finished device 232 in 1 seconds
INFO: worker Thread-11 finished device 165 in 1 seconds
INFO: worker Thread-4 finished device 220 in 1 seconds
INFO: worker Thread-10 finished device 250 in 1 seconds
INFO: worker Thread-3 finished device 194 in 1 seconds
INFO: worker Thread-2 finished device 164 in 1 seconds
INFO: worker Thread-9 finished device 213 in 1 seconds
INFO: worker Thread-14 finished device 229 in 1 seconds
INFO: worker Thread-15 finished device 226 in 1 seconds
INFO: worker Thread-12 finished device 212 in 1 seconds
INFO: worker Thread-1 finished device 245 in 1 seconds
INFO: worker Thread-16 finished device 211 in 1 seconds
INFO: worker Thread-13 finished device 210 in 1 seconds
INFO: worker Thread-6 finished device 218 in 1 seconds
INFO: worker Thread-5 finished device 197 in 1 seconds
INFO: worker Thread-8 finished device 221 in 1 seconds
INFO: worker Thread-7 finished device 248 in 1 seconds
INFO: worker Thread-11 finished device 222 in 1 seconds
INFO: worker Thread-4 finished device 177 in 1 seconds
INFO: worker Thread-10 finished device 207 in 1 seconds
INFO: worker Thread-3 finished device 223 in 1 seconds
INFO: worker Thread-2 finished device 243 in 1 seconds
INFO: poller-wrapper polled 105 devices in 21 seconds with 16 workers
*** Error in `python2': corrupted double-linked list: 0x0000559fa11d8740 ***
======= Backtrace: =========
/lib/x86_64-linux-gnu/libc.so.6(+0x70bfb)[0x7f1049be4bfb]
/lib/x86_64-linux-gnu/libc.so.6(+0x76fc6)[0x7f1049beafc6]
/lib/x86_64-linux-gnu/libc.so.6(+0x7804f)[0x7f1049bec04f]
python2(+0x111732)[0x559f9f201732]
python2(+0x1110ec)[0x559f9f2010ec]
python2(PyDict_SetItem+0x457)[0x559f9f1c8277]
python2(_PyModule_Clear+0x143)[0x559f9f22a7c3]
python2(PyImport_Cleanup+0x28f)[0x559f9f22a3bf]
python2(Py_Finalize+0x93)[0x559f9f228333]
python2(Py_Main+0x494)[0x559f9f1c5544]
/lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xf1)[0x7f1049b942e1]
python2(_start+0x2a)[0x559f9f1c4f9a]
======= Memory map: ========
559f9f0f0000-559f9f412000 r-xp 00000000 fe:00 10317                      /usr/bin/python2.7
559f9f612000-559f9f614000 r--p 00322000 fe:00 10317                      /usr/bin/python2.7
559f9f614000-559f9f68b000 rw-p 00324000 fe:00 10317                      /usr/bin/python2.7
559f9f68b000-559f9f6ae000 rw-p 00000000 00:00 0
559fa1109000-559fa12ea000 rw-p 00000000 00:00 0                          [heap]
7f0ff4000000-7f0ff4021000 rw-p 00000000 00:00 0
7f0ff4021000-7f0ff8000000 ---p 00000000 00:00 0
7f0ff8000000-7f0ff8021000 rw-p 00000000 00:00 0
7f0ff8021000-7f0ffc000000 ---p 00000000 00:00 0
7f0ffc000000-7f0ffc021000 rw-p 00000000 00:00 0
7f0ffc021000-7f1000000000 ---p 00000000 00:00 0
7f1002ffe000-7f1002fff000 ---p 00000000 00:00 0
7f1002fff000-7f10037ff000 rw-p 00000000 00:00 0
7f10037ff000-7f1003800000 ---p 00000000 00:00 0
7f1003800000-7f1004000000 rw-p 00000000 00:00 0
7f1004000000-7f1004021000 rw-p 00000000 00:00 0
7f1004021000-7f1008000000 ---p 00000000 00:00 0
7f1008000000-7f1008021000 rw-p 00000000 00:00 0
7f1008021000-7f100c000000 ---p 00000000 00:00 0
7f100c000000-7f100c021000 rw-p 00000000 00:00 0
7f100c021000-7f1010000000 ---p 00000000 00:00 0
7f1010000000-7f1010021000 rw-p 00000000 00:00 0
7f1010021000-7f1014000000 ---p 00000000 00:00 0
7f1014000000-7f1014021000 rw-p 00000000 00:00 0
7f1014021000-7f1018000000 ---p 00000000 00:00 0
7f1018000000-7f1018021000 rw-p 00000000 00:00 0
7f1018021000-7f101c000000 ---p 00000000 00:00 0
7f101c000000-7f101c021000 rw-p 00000000 00:00 0
7f101c021000-7f1020000000 ---p 00000000 00:00 0
7f1020000000-7f1020021000 rw-p 00000000 00:00 0
7f1020021000-7f1024000000 ---p 00000000 00:00 0
7f10247f9000-7f10247fa000 ---p 00000000 00:00 0
7f10247fa000-7f1024ffa000 rw-p 00000000 00:00 0
7f1024ffa000-7f1024ffb000 ---p 00000000 00:00 0
7f1024ffb000-7f10257fb000 rw-p 00000000 00:00 0
7f10257fb000-7f10257fc000 ---p 00000000 00:00 0
7f10257fc000-7f1025ffc000 rw-p 00000000 00:00 0
7f1025ffc000-7f1025ffd000 ---p 00000000 00:00 0
7f1025ffd000-7f10267fd000 rw-p 00000000 00:00 0
7f10267fd000-7f10267fe000 ---p 00000000 00:00 0
7f10267fe000-7f1026ffe000 rw-p 00000000 00:00 0
7f1026ffe000-7f1026fff000 ---p 00000000 00:00 0
7f1026fff000-7f10277ff000 rw-p 00000000 00:00 0
7f10277ff000-7f1027800000 ---p 00000000 00:00 0
7f1027800000-7f1028000000 rw-p 00000000 00:00 0
7f1028000000-7f1028021000 rw-p 00000000 00:00 0
7f1028021000-7f102c000000 ---p 00000000 00:00 0
7f102c000000-7f102c021000 rw-p 00000000 00:00 0
7f102c021000-7f1030000000 ---p 00000000 00:00 0
7f1030000000-7f1030021000 rw-p 00000000 00:00 0
7f1030021000-7f1034000000 ---p 00000000 00:00 0
7f1034000000-7f1034021000 rw-p 00000000 00:00 0
7f1034021000-7f1038000000 ---p 00000000 00:00 0
7f1038000000-7f1038021000 rw-p 00000000 00:00 0
7f1038021000-7f103c000000 ---p 00000000 00:00 0
7f103c000000-7f103c021000 rw-p 00000000 00:00 0
7f103c021000-7f1040000000 ---p 00000000 00:00 0
7f1040000000-7f1040021000 rw-p 00000000 00:00 0
7f1040021000-7f1044000000 ---p 00000000 00:00 0
7f104417a000-7f1044190000 r-xp 00000000 fe:00 259127                     /lib/x86_64-linux-gnu/libgcc_s.so.1
7f1044190000-7f104438f000 ---p 00016000 fe:00 259127                     /lib/x86_64-linux-gnu/libgcc_s.so.1
7f104438f000-7f1044390000 r--p 00015000 fe:00 259127                     /lib/x86_64-linux-gnu/libgcc_s.so.1
7f1044390000-7f1044391000 rw-p 00016000 fe:00 259127                     /lib/x86_64-linux-gnu/libgcc_s.so.1
7f1044391000-7f10443d1000 rw-p 00000000 00:00 0
7f10444d2000-7f10444d3000 ---p 00000000 00:00 0
7f10444d3000-7f1044cd3000 rw-p 00000000 00:00 0
7f1044dd4000-7f1044dd5000 ---p 00000000 00:00 0
7f1044dd5000-7f10455d5000 rw-p 00000000 00:00 0
7f10455d5000-7f10455d6000 ---p 00000000 00:00 0
7f10455d6000-7f1045dd6000 rw-p 00000000 00:00 0
7f1045dd6000-7f1045dd7000 ---p 00000000 00:00 0
7f1045dd7000-7f10465d7000 rw-p 00000000 00:00 0
7f10465d7000-7f10465d8000 ---p 00000000 00:00 0
7f10465d8000-7f1046dd8000 rw-p 00000000 00:00 0
7f1046ed9000-7f1046eda000 ---p 00000000 00:00 0
7f1046eda000-7f10476da000 rw-p 00000000 00:00 0
7f10477db000-7f10477dc000 ---p 00000000 00:00 0
7f10477dc000-7f1047fdc000 rw-p 00000000 00:00 0
7f1047fdc000-7f1047fdd000 ---p 00000000 00:00 0
7f1047fdd000-7f10487dd000 rw-p 00000000 00:00 0
7f10487dd000-7f10487e7000 r-xp 00000000 fe:00 259505                     /lib/x86_64-linux-gnu/libnss_files-2.24.so
7f10487e7000-7f10489e7000 ---p 0000a000 fe:00 259505                     /lib/x86_64-linux-gnu/libnss_files-2.24.so
7f10489e7000-7f10489e8000 r--p 0000a000 fe:00 259505                     /lib/x86_64-linux-gnu/libnss_files-2.24.so
7f10489e8000-7f10489e9000 rw-p 0000b000 fe:00 259505                     /lib/x86_64-linux-gnu/libnss_files-2.24.so
7f10489e9000-7f10489ef000 rw-p 00000000 00:00 0
7f10489ef000-7f1048aaf000 rw-p 00000000 00:00 0
7f1048aaf000-7f1048d60000 r-xp 00000000 fe:00 1788                       /usr/lib/x86_64-linux-gnu/libcrypto.so.1.1
7f1048d60000-7f1048f60000 ---p 002b1000 fe:00 1788                       /usr/lib/x86_64-linux-gnu/libcrypto.so.1.1
7f1048f60000-7f1048f90000 r--p 002b1000 fe:00 1788                       /usr/lib/x86_64-linux-gnu/libcrypto.so.1.1
7f1048f90000-7f1048f92000 rw-p 002e1000 fe:00 1788                       /usr/lib/x86_64-linux-gnu/libcrypto.so.1.1
7f1048f92000-7f1048f96000 rw-p 00000000 00:00 0
7f1048f96000-7f1049018000 r-xp 00000000 fe:00 1791                       /usr/lib/x86_64-linux-gnu/libssl.so.1.1
7f1049018000-7f1049218000 ---p 00082000 fe:00 1791                       /usr/lib/x86_64-linux-gnu/libssl.so.1.1
7f1049218000-7f1049221000 r--p 00082000 fe:00 1791                       /usr/lib/x86_64-linux-gnu/libssl.so.1.1
7f1049221000-7f1049225000 rw-p 0008b000 fe:00 1791                       /usr/lib/x86_64-linux-gnu/libssl.so.1.1
7f1049225000-7f104926c000 r-xp 00000000 fe:00 1215                       /usr/lib/x86_64-linux-gnu/libmariadb.so.3
7f104926c000-7f104946c000 ---p 00047000 fe:00 1215                       /usr/lib/x86_64-linux-gnu/libmariadb.so.3
7f104946c000-7f1049474000 r--p 00047000 fe:00 1215                       /usr/lib/x86_64-linux-gnu/libmariadb.so.3
7f1049474000-7f1049476000 rw-p 0004f000 fe:00 1215                       /usr/lib/x86_64-linux-gnu/libmariadb.so.3
7f1049476000-7f1049478000 rw-p 00000000 00:00 0
7f1049478000-7f1049482000 r-xp 00000000 fe:00 9516                       /usr/local/lib/python2.7/dist-packages/_mysql.so
7f1049482000-7f1049681000 ---p 0000a000 fe:00 9516                       /usr/local/lib/python2.7/dist-packages/_mysql.so
7f1049681000-7f1049682000 r--p 00009000 fe:00 9516                       /usr/local/lib/python2.7/dist-packages/_mysql.so
7f1049682000-7f1049686000 rw-p 0000a000 fe:00 9516                       /usr/local/lib/python2.7/dist-packages/_mysql.so
7f1049686000-7f10497c7000 rw-p 00000000 00:00 0
7f10497c7000-7f10497d7000 r-xp 00000000 fe:00 10597                      /usr/lib/python2.7/lib-dynload/_json.x86_64-linux-gnu.so
7f10497d7000-7f10499d6000 ---p 00010000 fe:00 10597                      /usr/lib/python2.7/lib-dynload/_json.x86_64-linux-gnu.so
7f10499d6000-7f10499d7000 r--p 0000f000 fe:00 10597                      /usr/lib/python2.7/lib-dynload/_json.x86_64-linux-gnu.so
7f10499d7000-7f10499d8000 rw-p 00010000 fe:00 10597                      /usr/lib/python2.7/lib-dynload/_json.x86_64-linux-gnu.so
7f10499d8000-7f1049b74000 r--p 00000000 fe:00 13861                      /usr/lib/locale/locale-archive
7f1049b74000-7f1049d09000 r-xp 00000000 fe:00 259472                     /lib/x86_64-linux-gnu/libc-2.24.so
7f1049d09000-7f1049f09000 ---p 00195000 fe:00 259472                     /lib/x86_64-linux-gnu/libc-2.24.so
7f1049f09000-7f1049f0d000 r--p 00195000 fe:00 259472                     /lib/x86_64-linux-gnu/libc-2.24.so
7f1049f0d000-7f1049f0f000 rw-p 00199000 fe:00 259472                     /lib/x86_64-linux-gnu/libc-2.24.so
7f1049f0f000-7f1049f13000 rw-p 00000000 00:00 0
7f1049f13000-7f104a016000 r-xp 00000000 fe:00 259499                     /lib/x86_64-linux-gnu/libm-2.24.so
7f104a016000-7f104a215000 ---p 00103000 fe:00 259499                     /lib/x86_64-linux-gnu/libm-2.24.so
7f104a215000-7f104a216000 r--p 00102000 fe:00 259499                     /lib/x86_64-linux-gnu/libm-2.24.so
7f104a216000-7f104a217000 rw-p 00103000 fe:00 259499                     /lib/x86_64-linux-gnu/libm-2.24.so
7f104a217000-7f104a230000 r-xp 00000000 fe:00 259219                     /lib/x86_64-linux-gnu/libz.so.1.2.8
7f104a230000-7f104a42f000 ---p 00019000 fe:00 259219                     /lib/x86_64-linux-gnu/libz.so.1.2.8
7f104a42f000-7f104a430000 r--p 00018000 fe:00 259219                     /lib/x86_64-linux-gnu/libz.so.1.2.8
7f104a430000-7f104a431000 rw-p 00019000 fe:00 259219                     /lib/x86_64-linux-gnu/libz.so.1.2.8
7f104a431000-7f104a433000 r-xp 00000000 fe:00 259514                     /lib/x86_64-linux-gnu/libutil-2.24.so
7f104a433000-7f104a632000 ---p 00002000 fe:00 259514                     /lib/x86_64-linux-gnu/libutil-2.24.so
7f104a632000-7f104a633000 r--p 00001000 fe:00 259514                     /lib/x86_64-linux-gnu/libutil-2.24.so
7f104a633000-7f104a634000 rw-p 00002000 fe:00 259514                     /lib/x86_64-linux-gnu/libutil-2.24.so
7f104a634000-7f104a637000 r-xp 00000000 fe:00 259497                     /lib/x86_64-linux-gnu/libdl-2.24.so
7f104a637000-7f104a836000 ---p 00003000 fe:00 259497                     /lib/x86_64-linux-gnu/libdl-2.24.so
7f104a836000-7f104a837000 r--p 00002000 fe:00 259497                     /lib/x86_64-linux-gnu/libdl-2.24.so
7f104a837000-7f104a838000 rw-p 00003000 fe:00 259497                     /lib/x86_64-linux-gnu/libdl-2.24.so
7f104a838000-7f104a850000 r-xp 00000000 fe:00 259510                     /lib/x86_64-linux-gnu/libpthread-2.24.so
7f104a850000-7f104aa4f000 ---p 00018000 fe:00 259510                     /lib/x86_64-linux-gnu/libpthread-2.24.so
7f104aa4f000-7f104aa50000 r--p 00017000 fe:00 259510                     /lib/x86_64-linux-gnu/libpthread-2.24.so
7f104aa50000-7f104aa51000 rw-p 00018000 fe:00 259510                     /lib/x86_64-linux-gnu/libpthread-2.24.so
7f104aa51000-7f104aa55000 rw-p 00000000 00:00 0
7f104aa55000-7f104aa78000 r-xp 00000000 fe:00 259407                     /lib/x86_64-linux-gnu/ld-2.24.so
7f104aa7a000-7f104ab7a000 rw-p 00000000 00:00 0
7f104abab000-7f104ac6f000 rw-p 00000000 00:00 0
7f104ac77000-7f104ac78000 rw-p 00000000 00:00 0
7f104ac78000-7f104ac79000 r--p 00023000 fe:00 259407                     /lib/x86_64-linux-gnu/ld-2.24.so
7f104ac79000-7f104ac7a000 rw-p 00024000 fe:00 259407                     /lib/x86_64-linux-gnu/ld-2.24.so
7f104ac7a000-7f104ac7b000 rw-p 00000000 00:00 0
7ffcdc930000-7ffcdc951000 rw-p 00000000 00:00 0                          [stack]
7ffcdc991000-7ffcdc993000 r--p 00000000 00:00 0                          [vvar]
7ffcdc993000-7ffcdc995000 r-xp 00000000 00:00 0                          [vdso]
ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0                  [vsyscall]
Aborted

I have also tried running poller-wrapper.py with 3 threads (50% of cores), but no luck.

validate.php:

root@librenms0:/opt/librenms# ./validate.php
====================================
Component | Version
--------- | -------
LibreNMS  | 1.61-188-gb9171c929
DB Schema | 2020_02_10_223323_create_alert_location_map_table (159)
PHP       | 7.2.29-1+0~20200320.39+debian9~1.gbp513c2e
MySQL     | 10.3.22-MariaDB-1:10.3.22+maria~stretch
RRDTool   | 1.6.0
SNMP      | NET-SNMP 5.7.3
====================================

[OK]    Composer Version: 1.10.1
[OK]    Dependencies up-to-date.
[OK]    Database connection successful
[OK]    Database schema correct
[FAIL]  Some folders have incorrect file permissions, this may cause issues.
	[FIX]:
	sudo chown -R librenms:librenms /opt/librenms
	sudo setfacl -d -m g::rwx /opt/librenms/rrd /opt/librenms/logs /opt/librenms/bootstrap/cache/ /opt/librenms/storage/
	sudo chmod -R ug=rwX /opt/librenms/rrd /opt/librenms/logs /opt/librenms/bootstrap/cache/ /opt/librenms/storage/
	Files:
	 /opt/librenms/bootstrap/cache/packages.php

System information:

root@librenms0:~# uname -r
4.9.0-12-amd64

root@librenms0:~# lsb_release -a
No LSB modules are available.
Distributor ID:	Debian
Description:	Debian GNU/Linux 9.12 (stretch)
Release:	9.12
Codename:	stretch

root@librenms0:~# cat /proc/cpuinfo
processor	: 0
vendor_id	: GenuineIntel
cpu family	: 6
model		: 85
model name	: Intel(R) Xeon(R) Silver 4214 CPU @ 2.20GHz
stepping	: 7
microcode	: 0x1
cpu MHz		: 2199.998
cache size	: 16384 KB
physical id	: 0
siblings	: 6
core id		: 0
cpu cores	: 6
apicid		: 0
initial apicid	: 0
fpu		: yes
fpu_exception	: yes
cpuid level	: 13
wp		: yes
flags		: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ss ht syscall nx pdpe1gb rdtscp lm constant_tsc arch_perfmon rep_good nopl xtopology pni pclmulqdq ssse3 fma cx16 pcid sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand hypervisor lahf_lm abm 3dnowprefetch invpcid_single ssbd ibrs ibpb kaiser fsgsbase tsc_adjust bmi1 avx2 smep bmi2 erms invpcid mpx avx512f avx512dq rdseed adx smap clflushopt clwb avx512cd avx512bw avx512vl xsaveopt xsavec xgetbv1 xsaves arat pku ospke md_clear
bugs		: cpu_meltdown spectre_v1 spectre_v2 spec_store_bypass l1tf mds swapgs itlb_multihit
bogomips	: 4399.99
clflush size	: 64
cache_alignment	: 64
address sizes	: 40 bits physical, 48 bits virtual
power management:

processor	: 1
vendor_id	: GenuineIntel
cpu family	: 6
model		: 85
model name	: Intel(R) Xeon(R) Silver 4214 CPU @ 2.20GHz
stepping	: 7
microcode	: 0x1
cpu MHz		: 2199.998
cache size	: 16384 KB
physical id	: 0
siblings	: 6
core id		: 1
cpu cores	: 6
apicid		: 1
initial apicid	: 1
fpu		: yes
fpu_exception	: yes
cpuid level	: 13
wp		: yes
flags		: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ss ht syscall nx pdpe1gb rdtscp lm constant_tsc arch_perfmon rep_good nopl xtopology pni pclmulqdq ssse3 fma cx16 pcid sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand hypervisor lahf_lm abm 3dnowprefetch invpcid_single ssbd ibrs ibpb kaiser fsgsbase tsc_adjust bmi1 avx2 smep bmi2 erms invpcid mpx avx512f avx512dq rdseed adx smap clflushopt clwb avx512cd avx512bw avx512vl xsaveopt xsavec xgetbv1 xsaves arat pku ospke md_clear
bugs		: cpu_meltdown spectre_v1 spectre_v2 spec_store_bypass l1tf mds swapgs itlb_multihit
bogomips	: 4399.99
clflush size	: 64
cache_alignment	: 64
address sizes	: 40 bits physical, 48 bits virtual
power management:

processor	: 2
vendor_id	: GenuineIntel
cpu family	: 6
model		: 85
model name	: Intel(R) Xeon(R) Silver 4214 CPU @ 2.20GHz
stepping	: 7
microcode	: 0x1
cpu MHz		: 2199.998
cache size	: 16384 KB
physical id	: 0
siblings	: 6
core id		: 2
cpu cores	: 6
apicid		: 2
initial apicid	: 2
fpu		: yes
fpu_exception	: yes
cpuid level	: 13
wp		: yes
flags		: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ss ht syscall nx pdpe1gb rdtscp lm constant_tsc arch_perfmon rep_good nopl xtopology pni pclmulqdq ssse3 fma cx16 pcid sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand hypervisor lahf_lm abm 3dnowprefetch invpcid_single ssbd ibrs ibpb kaiser fsgsbase tsc_adjust bmi1 avx2 smep bmi2 erms invpcid mpx avx512f avx512dq rdseed adx smap clflushopt clwb avx512cd avx512bw avx512vl xsaveopt xsavec xgetbv1 xsaves arat pku ospke md_clear
bugs		: cpu_meltdown spectre_v1 spectre_v2 spec_store_bypass l1tf mds swapgs itlb_multihit
bogomips	: 4399.99
clflush size	: 64
cache_alignment	: 64
address sizes	: 40 bits physical, 48 bits virtual
power management:

processor	: 3
vendor_id	: GenuineIntel
cpu family	: 6
model		: 85
model name	: Intel(R) Xeon(R) Silver 4214 CPU @ 2.20GHz
stepping	: 7
microcode	: 0x1
cpu MHz		: 2199.998
cache size	: 16384 KB
physical id	: 0
siblings	: 6
core id		: 3
cpu cores	: 6
apicid		: 3
initial apicid	: 3
fpu		: yes
fpu_exception	: yes
cpuid level	: 13
wp		: yes
flags		: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ss ht syscall nx pdpe1gb rdtscp lm constant_tsc arch_perfmon rep_good nopl xtopology pni pclmulqdq ssse3 fma cx16 pcid sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand hypervisor lahf_lm abm 3dnowprefetch invpcid_single ssbd ibrs ibpb kaiser fsgsbase tsc_adjust bmi1 avx2 smep bmi2 erms invpcid mpx avx512f avx512dq rdseed adx smap clflushopt clwb avx512cd avx512bw avx512vl xsaveopt xsavec xgetbv1 xsaves arat pku ospke md_clear
bugs		: cpu_meltdown spectre_v1 spectre_v2 spec_store_bypass l1tf mds swapgs itlb_multihit
bogomips	: 4399.99
clflush size	: 64
cache_alignment	: 64
address sizes	: 40 bits physical, 48 bits virtual
power management:

processor	: 4
vendor_id	: GenuineIntel
cpu family	: 6
model		: 85
model name	: Intel(R) Xeon(R) Silver 4214 CPU @ 2.20GHz
stepping	: 7
microcode	: 0x1
cpu MHz		: 2199.998
cache size	: 16384 KB
physical id	: 0
siblings	: 6
core id		: 4
cpu cores	: 6
apicid		: 4
initial apicid	: 4
fpu		: yes
fpu_exception	: yes
cpuid level	: 13
wp		: yes
flags		: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ss ht syscall nx pdpe1gb rdtscp lm constant_tsc arch_perfmon rep_good nopl xtopology pni pclmulqdq ssse3 fma cx16 pcid sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand hypervisor lahf_lm abm 3dnowprefetch invpcid_single ssbd ibrs ibpb kaiser fsgsbase tsc_adjust bmi1 avx2 smep bmi2 erms invpcid mpx avx512f avx512dq rdseed adx smap clflushopt clwb avx512cd avx512bw avx512vl xsaveopt xsavec xgetbv1 xsaves arat pku ospke md_clear
bugs		: cpu_meltdown spectre_v1 spectre_v2 spec_store_bypass l1tf mds swapgs itlb_multihit
bogomips	: 4399.99
clflush size	: 64
cache_alignment	: 64
address sizes	: 40 bits physical, 48 bits virtual
power management:

processor	: 5
vendor_id	: GenuineIntel
cpu family	: 6
model		: 85
model name	: Intel(R) Xeon(R) Silver 4214 CPU @ 2.20GHz
stepping	: 7
microcode	: 0x1
cpu MHz		: 2199.998
cache size	: 16384 KB
physical id	: 0
siblings	: 6
core id		: 5
cpu cores	: 6
apicid		: 5
initial apicid	: 5
fpu		: yes
fpu_exception	: yes
cpuid level	: 13
wp		: yes
flags		: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ss ht syscall nx pdpe1gb rdtscp lm constant_tsc arch_perfmon rep_good nopl xtopology pni pclmulqdq ssse3 fma cx16 pcid sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand hypervisor lahf_lm abm 3dnowprefetch invpcid_single ssbd ibrs ibpb kaiser fsgsbase tsc_adjust bmi1 avx2 smep bmi2 erms invpcid mpx avx512f avx512dq rdseed adx smap clflushopt clwb avx512cd avx512bw avx512vl xsaveopt xsavec xgetbv1 xsaves arat pku ospke md_clear
bugs		: cpu_meltdown spectre_v1 spectre_v2 spec_store_bypass l1tf mds swapgs itlb_multihit
bogomips	: 4399.99
clflush size	: 64
cache_alignment	: 64
address sizes	: 40 bits physical, 48 bits virtual
power management:

root@librenms0:~# df -h
Filesystem                            Size  Used Avail Use% Mounted on
udev                                  991M     0  991M   0% /dev
tmpfs                                 201M  8.1M  193M   5% /run
/dev/mapper/WebNodeTemplate--vg-root   88G   37G   48G  43% /
tmpfs                                1002M  4.0K 1002M   1% /dev/shm
tmpfs                                 5.0M     0  5.0M   0% /run/lock
tmpfs                                1002M     0 1002M   0% /sys/fs/cgroup
/dev/sda1                             236M   63M  161M  28% /boot
tmpfs                                 201M     0  201M   0% /run/user/0

root@librenms0:~# python --version
Python 2.7.13

Just upgraded to Debian 10, now running Python 2.7.16. Getting a different segfault now:

INFO: worker Thread-1 finished device 164 in 1 seconds
INFO: worker Thread-2 finished device 245 in 2 seconds
INFO: worker Thread-3 finished device 250 in 2 seconds
INFO: worker Thread-2 finished device 243 in 4 seconds
INFO: worker Thread-3 finished device 165 in 4 seconds
INFO: worker Thread-1 finished device 220 in 4 seconds
INFO: worker Thread-2 finished device 190 in 1 seconds
INFO: worker Thread-3 finished device 211 in 1 seconds
) = 0
write(1, "INFO: poller-wrapper polled 103 "..., 70INFO: poller-wrapper polled 103 devices in 119 seconds with 3 workers
) = 70
getpid()                                = 1700
socket(AF_UNIX, SOCK_STREAM, 0)         = 3
fcntl(3, F_SETFL, O_RDONLY|O_NONBLOCK)  = 0
connect(3, {sa_family=AF_UNIX, sun_path="/var/run/mysqld/mysqld.sock"}, 110) = 0
fcntl(3, F_SETFL, O_RDONLY)             = 0
setsockopt(3, SOL_IP, IP_TOS, [8], 4)   = -1 EOPNOTSUPP (Operation not supported)
setsockopt(3, SOL_SOCKET, SO_KEEPALIVE, [1], 4) = 0
recvfrom(3, "q\0\0\0\n5.5.5-10.4.12-MariaDB-1:10."..., 16384, MSG_DONTWAIT, NULL, NULL) = 117
sendto(3, "\310\0\0\1\214\242\237\0\0\0\0@\10\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 204, MSG_DONTWAIT|MSG_NOSIGNAL, NULL, 0) = 204
recvfrom(3, "\24\0\0\2\0\0\0\2@\0\0\0\v\1\t\10librenms", 16384, MSG_DONTWAIT, NULL, NULL) = 24
setsockopt(3, SOL_SOCKET, SO_RCVTIMEO, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0", 16) = 0
setsockopt(3, SOL_SOCKET, SO_SNDTIMEO, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0", 16) = 0
sendto(3, "\21\0\0\0\3SET autocommit=0", 21, MSG_DONTWAIT|MSG_NOSIGNAL, NULL, 0) = 21
recvfrom(3, "\32\0\0\1\0\0\0\0@\0\0\0\21\0\17\nautocommit\3OFF", 16384, MSG_DONTWAIT, NULL, NULL) = 30
stat("/usr/lib/python2.7/encodings/latin_1", 0x7ffed1aa0cd0) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/lib/python2.7/encodings/latin_1.x86_64-linux-gnu.so", O_RDONLY) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/lib/python2.7/encodings/latin_1.so", O_RDONLY) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/lib/python2.7/encodings/latin_1module.so", O_RDONLY) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/lib/python2.7/encodings/latin_1.py", O_RDONLY) = 4
fstat(4, {st_mode=S_IFREG|0644, st_size=1264, ...}) = 0
openat(AT_FDCWD, "/usr/lib/python2.7/encodings/latin_1.pyc", O_RDONLY) = 5
fstat(5, {st_mode=S_IFREG|0644, st_size=2291, ...}) = 0
read(5, "\3\363\r\ng\252\237]c\0\0\0\0\0\0\0\0\3\0\0\0@\0\0\0s\273\0\0\0d\0"..., 4096) = 2291
fstat(5, {st_mode=S_IFREG|0644, st_size=2291, ...}) = 0
read(5, "", 4096)                       = 0
close(5)                                = 0
mmap(NULL, 262144, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f180a659000
close(4)                                = 0
sendto(3, "z\0\0\0\3update pollers set last_pol"..., 126, MSG_DONTWAIT|MSG_NOSIGNAL, NULL, 0) = 126
recvfrom(3, "0\0\0\1\0\1\0\1\0\0\0(Rows matched: 1  Cha"..., 16384, MSG_DONTWAIT, NULL, NULL) = 52
sendto(3, "\7\0\0\0\3COMMIT", 11, MSG_DONTWAIT|MSG_NOSIGNAL, NULL, 0) = 11
recvfrom(3, 0x55d53bcc9320, 16384, MSG_DONTWAIT, NULL, NULL) = -1 EAGAIN (Resource temporarily unavailable)
poll([{fd=3, events=POLLIN}], 1, -1)    = 1 ([{fd=3, revents=POLLIN}])
recvfrom(3, "\7\0\0\1\0\0\0\0\0\0\0", 16384, MSG_DONTWAIT, NULL, NULL) = 11
sendto(3, "\1\0\0\0\1", 5, MSG_DONTWAIT|MSG_NOSIGNAL, NULL, 0) = 5
close(3)                                = 0
--- SIGSEGV {si_signo=SIGSEGV, si_code=SEGV_MAPERR, si_addr=0xcf6a908} ---
+++ killed by SIGSEGV +++
Segmentation fault

‘Fixed’ by using the patch at Python 3 support for poller-wrapper.py and some of my own patches.