ERROR: Job failed: command terminated with exit code 137 (auto retry not working)

Summary

From time to time (1/30 jobs) I get job failing suddenly with exit code 137.

Steps to reproduce

It happens randomly, all runners are kubernetes executor.

What is the current bug behavior?

All jobs are configured with

  retry:
    max: 2
    when:
      - runner_system_failure
      - stuck_or_timeout_failure
      - unknown_failure

The job is marked as failed and it doesn't retry it automatically.

What is the expected correct behavior?

I would expect that auto retry come into action but it doesn't.

Relevant logs and/or screenshots

$ skt -vv --state --junit junit --rc ${RC_FILE} --workdir ${WORKDIR} build --makeopts=-j$(nproc) --cfgtype rh-configs --rh-configs-glob 'redhat/configs/kernel-*-'"${ARCH_CONFIG}"'.config'
2018-12-05 21:23:53,644     INFO   basecfg: None
2018-12-05 21:23:53,644     INFO   cfgtype: rh-configs
2018-12-05 21:23:53,644     INFO   building kernel: ['make', '-C', '/cki-project/cki-pipeline/workdir', 'INSTALL_MOD_STRIP=1', '-j64', 'targz-pkg', '-j64']
2018-12-05 21:23:53,645     INFO   building Red Hat configs: ['make', '-C', '/cki-project/cki-pipeline/workdir', 'rh-configs']
ERROR: Job failed: command terminated with exit code 137

Results of GitLab environment info

gitlab-rake gitlab:env:info

System information
System:
Current User:   git
Using RVM:      no
Ruby Version:   2.4.5p335
Gem Version:    2.7.6
Bundler Version:1.16.6
Rake Version:   12.3.1
Redis Version:  3.2.12
Git Version:    2.18.1
Sidekiq Version:5.2.1
Go Version:     unknown

GitLab information
Version:        11.5.1
Revision:       c90ae59
Directory:      /opt/gitlab/embedded/service/gitlab-rails
DB Adapter:     postgresql
URL:            https://xci32.lab.eng.rdu2.redhat.com
HTTP Clone URL: https://xci32.lab.eng.rdu2.redhat.com/some-group/some-project.git
SSH Clone URL:  git@xci32.lab.eng.rdu2.redhat.com:some-group/some-project.git
Using LDAP:     no
Using Omniauth: yes
Omniauth Providers:

GitLab Shell
Version:        8.4.1
Repository storage paths:
- default:      /var/opt/gitlab/git-data/repositories
Hooks:          /opt/gitlab/embedded/service/gitlab-shell/hooks
Git:            /opt/gitlab/embedded/bin/git

Results of GitLab application Check

gitlab-rake gitlab:check SANITIZE=true                                                                                                                                                                                [8/1966]
Checking GitLab Shell ...

GitLab Shell version >= 8.4.1 ? ... OK (8.4.1)
hooks directories in repos are links: ...
36/1 ... ok
36/2 ... ok
38/3 ... ok
38/4 ... ok
Running /opt/gitlab/embedded/service/gitlab-shell/bin/check
Check GitLab API access: OK
Redis available via internal API: OK

Access to /var/opt/gitlab/.ssh/authorized_keys: OK
gitlab-shell self-check successful

Checking GitLab Shell ... Finished

Checking Gitaly ...

default ... OK

Checking Gitaly ... Finished

Checking Sidekiq ...

Running? ... yes
Number of Sidekiq processes ... 1

Checking Sidekiq ... Finished

Reply by email is disabled in config/gitlab.yml
Checking LDAP ...

LDAP is disabled in config/gitlab.yml

Checking LDAP ... Finished

Checking GitLab ...

Git configured correctly? ... yes
Database config exists? ... yes
All migrations up? ... yes
Database contains orphaned GroupMembers? ... no
GitLab config exists? ... yes
GitLab config up to date? ... yes
Log directory writable? ... yes
Tmp directory writable? ... yes
Uploads directory exists? ... yes
Uploads directory has correct permissions? ... yes
Uploads directory tmp has correct permissions? ... skipped (no tmp uploads folder yet)
Init script exists? ... skipped (omnibus-gitlab has no init script)
Init script up-to-date? ... skipped (omnibus-gitlab has no init script)
Projects have namespace: ...
36/1 ... yes
36/2 ... yes
38/3 ... yes
38/4 ... yes
Redis version >= 2.8.0? ... yes
Ruby version >= 2.3.5 ? ... yes (2.4.5)
Git version >= 2.9.5 ? ... yes (2.18.1)
Git user has default SSH configuration? ... yes
Active users: ... 6

Checking GitLab ... Finished