fetchlimit system test fails intermittently

One failure has been observed so far:

• https://gitlab.isc.org/isc-projects/bind9/-/jobs/940

S:fetchlimit:Wed Feb 14 15:04:15 UTC 2018
T:fetchlimit:1:A
A:System test fetchlimit
I: checking recursing clients are dropped at the per-server limit
I: clients: 20
I: clients: 40
I: clients: 60
I: clients: 80
I: clients: 100
I: clients: 120
I: clients: 140
I: clients: 160
I: clients: 180
I: clients: 180
I: clients: 180
I: clients: 165
I: clients: 152
I: clients: 141
I: clients: 131
I: clients: 131
I: clients: 122
I: clients: 114
I: clients: 114
I: clients: 107
I: dumping ADB data
I: atr 1.00 quota 107
I: checking servfail statistics
I: checking lame server recovery
I: clients: 63
I: clients: 24
I: clients: 3
I: clients: 4
I: clients: 6
I: dumping ADB data
I: atr 0.51 quota 95
I: clients: 3
I: clients: 1
I: clients: 1
I: clients: 0
I: clients: 9
I: clients: 0
I: clients: 0
I: clients: 0
I: clients: 0
I: clients: 6
I: dumping ADB data
I: atr 0.06 quota 101
I: checking lame server clients are dropped at the per-domain limit
I: clients: 40
I: clients: 40
I: clients: 40
I: clients: 40
I: clients: 40
I: 5 successful valid queries, 0 SERVFAIL
I: checking drop statistics
I: checking lame server clients are dropped at the soft limit
I: clients: 361
I: 1 successful valid queries, 0 SERVFAIL
I: failed
I:exit status: 1
R:FAIL
E:fetchlimit:Wed Feb 14 15:05:10 UTC 2018

Test artifacts are not available as they were not yet collected when the failure happened.