dyndb system test fails intermittently

Three failures have been observed so far:

S:dyndb:Thu Feb 22 12:21:06 UTC 2018
T:dyndb:1:A
A:dyndb:System test dyndb
I:dyndb:PORTRANGE:5300 - 5399
I:adding test1.ipv4.example.nil. A 10.53.0.10 (1)
I:adding test2.ipv4.example.nil. A 10.53.0.11 (2)
I:adding test3.ipv4.example.nil. A 10.53.0.12 (3)
I:adding test4.ipv6.example.nil. AAAA 2001:db8::1 (4)
I:deleting test1.ipv4.example.nil. A (was 10.53.0.10) (5)
I:deleting test2.ipv4.example.nil. A (was 10.53.0.11) (6)
I:deleting test3.ipv4.example.nil. A (was 10.53.0.12) (7)
I:deleting test4.ipv6.example.nil. AAAA (was 2001:db8::1) (8)
I:checking parameter logging (9)
I:checking dyndb still works after reload
I:ns1 server reload successful
I:adding test5.ipv4.example.nil. A 10.53.0.10 (10)
I:adding test6.ipv6.example.nil. AAAA 2001:db8::1 (11)
I:deleting test5.ipv4.example.nil. A (was 10.53.0.10) (12)
I:deleting test6.ipv6.example.nil. AAAA (was 2001:db8::1) (13)
I:exit status: 1
R:dyndb:FAIL
E:dyndb:Thu Feb 22 12:21:11 UTC 2018

Repacked artifacts (removed .o, .a and .libs) from the first failure attached: dyndb-artifacts.tar.xz

Edited Feb 23, 2018 by Michał Kępień