Description of problem:

Recently, all my beaker jobs with ipv6.disable=1 are aborted.

And just find this failure:
xxx-yyy-zzz login: [   43.569051] traps: restraintd[1960] trap int3 ip:5fcdf1 sp:7fffbac49550 error:0 in restraintd[400000+6da000] 
[-- MARK -- Tue May 19 10:05:00 2020] 
[-- MARK -- Tue May 19 10:10:00 2020]  

Version-Release number of selected component (if applicable):
restraint-0.2.0-1.el7bkr
restraint-0.2.0-1.el8bkr

How reproducible:
always

Steps to Reproduce:
1. $ grubby --args=ipv6.disable=1 --update-kernel=DEFAULT
2. Then reboot
3.

Actual results:
# beaker jobs
https://beaker.engineering.redhat.com/jobs/4263822 (rhel7)
https://beaker.engineering.redhat.com/jobs/4263814 (rhel7)
https://beaker.engineering.redhat.com/jobs/4263294 (rhel8)
https://beaker.engineering.redhat.com/jobs/4263497 (rhel8)

# from console.log
hp-dl360g9-15 login: [   39.091217] restraintd[2912]: * Fetching recipe: http://lab-01.rhts.eng.pek2.redhat.com:8000//recipes/8260137/ 
[   40.485163] restraintd[2912]: * Parsing recipe 
[   40.486729] restraintd[2912]: * Running recipe 
[   40.487298] restraintd[2912]: ** Fetching task: 110417409 [/mnt/tests/distribution/check-install] 
[   50.407696] restraintd[2912]: ** Preparing metadata 
[   50.409477] restraintd[2912]: ** Refreshing peer role hostnames: Retries 0 
[   51.802074] restraintd[2912]: ** Updating env vars 
[   51.803158] restraintd[2912]: ** Updating external watchdog: 2400 seconds 
[   53.149518] restraintd[2912]: ** Installing dependencies 
[   53.153067] restraintd[2912]: ** Running task: 110417409 [/distribution/check-install] 
[   71.361533] restraintd[2912]: ** Completed Task : 110417409 
[   72.714470] restraintd[2912]: ** Fetching task: 110417410 [/mnt/tests/distribution/Library/epel] 
[   77.002207] restraintd[2912]: ** Preparing metadata 
[   77.003398] restraintd[2912]: ** Refreshing peer role hostnames: Retries 0 
[   78.407147] restraintd[2912]: ** Updating env vars 
[   78.408048] restraintd[2912]: ** Updating external watchdog: 3300 seconds 
[   79.749667] restraintd[2912]: ** Installing dependencies 
[   80.681239] restraintd[2912]: ** Running task: 110417410 [/distribution/Library/epel] 
[   93.277535] restraintd[2912]: ** Completed Task : 110417410 
[   94.631590] restraintd[2912]: ** Fetching task: 110417411 [/mnt/tests/distribution/command] 
[  113.761362] restraintd[2912]: ** Preparing metadata 
[  113.762914] restraintd[2912]: ** Refreshing peer role hostnames: Retries 0 
[  115.171623] restraintd[2912]: ** Updating env vars 
[  115.172611] restraintd[2912]: ** Updating external watchdog: 30600 seconds 
[  116.474366] restraintd[2912]: ** Installing dependencies 
[  116.478518] restraintd[2912]: ** Running task: 110417411 [/distribution/command] 
[  122.651229] restraintd[2912]: ** Completed Task : 110417411 
[  123.964061] restraintd[2912]: ** Fetching task: 110417412 [/mnt/tests/distribution/utils/reboot] 
[  128.421414] restraintd[2912]: ** Preparing metadata 
[  128.422595] restraintd[2912]: ** Refreshing peer role hostnames: Retries 0 
[  129.831345] restraintd[2912]: ** Updating env vars 
[  129.832291] restraintd[2912]: ** Updating external watchdog: 2400 seconds 
[  131.132613] restraintd[2912]: ** Installing dependencies 
[  131.136588] restraintd[2912]: ** Running task: 110417412 [/distribution/utils/reboot] 
[  135.754919] traps: restraintd[2912] trap int3 ip:5fcdf1 sp:7ffdbaaa9bd0 error:0 in restraintd[400000+6da000] 

Expected results:
start machine with ipv6 disabled

Additional info:
# pass with harness=beah
https://beaker.engineering.redhat.com/jobs/4263820