After deleting build artifacts, empty logfile and empty artifacts folder still persists on the filesystem

Summary

I recently cleaned the builds of a testing repository and deleted the build artifacts by using the provided button. After deleting i can see the info message "Job has been erased by %USERNAME% X days ago" which is correct. But there is still an empty log file with the job id in its name and an empty folder for the artifacts on the filesystem.

Steps to reproduce

Go into your Pipelines and select a job which had artifacts. Remove them by using the provided button. Now ssh into the server and go to /var/opt/gitlab/gitlab-ci/builds/YEAR_MONTH/PROJECTID/ and there should be a file with 0 b size with the name BUILDUMBER.log.
Also go to /var/opt/gitlab/gitlab-rails/shared/artifacts/YEAR_MONTH/PROJECTID there should be a folder named by the buildnumer without any contents in it.

What is the current bug behavior?

The log file and the artifact folder seems to be just emptied.

What is the expected correct behavior?

The log file should be deleted, not just emptied. And the artifacts folder also.

Relevant logs and/or screenshots

Output of checks

(If you are reporting a bug on GitLab.com, write: This bug happens on GitLab.com)

Results of GitLab environment info

System information
System:		Debian 8.7
Current User:	git
Using RVM:	no
Ruby Version:	2.3.3p222
Gem Version:	2.6.6
Bundler Version:1.13.7
Rake Version:	10.5.0
Redis Version:	3.2.5
Sidekiq Version:4.2.7

GitLab information
Version:	8.17.2
Revision:	bab14bd
Directory:	/opt/gitlab/embedded/service/gitlab-rails
DB Adapter:	postgresql
URL:		https://TLD.de
HTTP Clone URL:	https://TLD.de/some-group/some-project.git
SSH Clone URL:	git@TLD.de:some-group/some-project.git
Using LDAP:	no
Using Omniauth:	no

GitLab Shell
Version:	4.1.1
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

Checking GitLab Shell ...

GitLab Shell version >= 4.1.1 ? ... OK (4.1.1)
Repo base directory exists?
default... yes
Repo storage directories are symlinks?
default... no
Repo paths owned by git:git?
default... yes
Repo paths access is drwxrws---?
default... yes
hooks directories in repos are links: ... 
5/5 ... ok
5/6 ... ok
5/7 ... ok
5/8 ... ok
5/12 ... ok
4/13 ... ok
5/14 ... ok
5/15 ... ok
14/17 ... ok
19/21 ... ok
3/23 ... ok
5/26 ... ok
28/29 ... ok
14/30 ... ok
5/31 ... ok
26/33 ... ok
4/34 ... ok
3/35 ... ok
14/36 ... repository is empty
3/38 ... ok
3/39 ... ok
Running /opt/gitlab/embedded/service/gitlab-shell/bin/check
Check GitLab API access: OK
Access to /var/opt/gitlab/.ssh/authorized_keys: OK
Send ping to redis server: OK
gitlab-shell self-check successful

Checking GitLab Shell ... Finished

Checking Sidekiq ...

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

Checking Sidekiq ... Finished

Checking Reply by email ...

Reply by email is disabled in config/gitlab.yml

Checking Reply by email ... Finished

Checking LDAP ...

LDAP is disabled in config/gitlab.yml

Checking LDAP ... Finished

Checking GitLab ...

Git configured with autocrlf=input? ... yes
Database config exists? ... yes
All migrations up? ... yes
Database contains orphaned GroupMembers? ... no
GitLab config exists? ... yes
GitLab config outdated? ... no
Log directory writable? ... yes
Tmp directory writable? ... yes
Uploads directory setup correctly? ... yes
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: ... 
5/5 ... yes
5/6 ... yes
5/7 ... yes
5/8 ... yes
5/12 ... yes
4/13 ... yes
5/14 ... yes
5/15 ... yes
14/17 ... yes
19/21 ... yes
3/23 ... yes
5/26 ... yes
28/29 ... yes
14/30 ... yes
5/31 ... yes
26/33 ... yes
4/34 ... yes
3/35 ... yes
14/36 ... yes
3/38 ... yes
3/39 ... yes
Redis version >= 2.8.0? ... yes
Ruby version >= 2.1.0 ? ... yes (2.3.3)
Your git bin path is "/opt/gitlab/embedded/bin/git"
Git version >= 2.7.3 ? ... yes (2.10.2)
Active users: 32

Checking GitLab ... Finished

Possible fixes

can`t provide any, sry.