Issues can't show related branches and issue board is unavailable when using relative urls

Summary

When using the issues interface, I receive an error: Failed to load related branches

Steps to reproduce

Set up gitlab in relative url mode. Using /gitlab

What is the current bug behavior?

Screenshot_from_2017-11-24_23-18-05

Screenshot_from_2017-11-24_23-16-19

What is the expected correct behavior?

I believe I should see the related branches, and the board should work.

Results of GitLab environment info

Expand for output related to GitLab environment info 
(For installations with omnibus-gitlab package run and paste the output of:
sudo gitlab-rake gitlab:env:info)


System information:
System: openSUSE project 42.3
Current User: git
Using RVM: no
Ruby Version: 2.3.5p376
Gem Version: 2.6.12
Bundler Version: 1.13.7
Rake Version 12.1.0
Redis Version: 3.2.5
Git Version: 2.13.6
Sidekiq Version: 5.0.4
Go Version: go1.7.5 linux/amd64


GitLab information
Version: 10.2.1
Revision: eb2643f
Directory: /opt/gitlab/embedded/service/gitlab-rails
DB Adapter: postgresql
URL: http://bioemergences.eu/gitlab
HTTP Clone URL: http://bioemergences.eu/gitlab/some-group/some-project.git
SSH Clone URL: git@bioemergences.eu:some-group/some-project.git
Using LDAP: no
Using Omniauth: no


GitLab Shell:
Version: 5.9.4
Repository storage paths:
  • default: /var/opt/gitlab/git-data/repositories Hooks: /opt/gitlab/embedded/service/gitlab-shell/hooks Git: /opt/gitlab/embedded/bin/git

note: I'm pretty new to gitlab, so I don't know what logs to look in to help you guys

Results of GitLab application Check

Expand for output related to the GitLab application check 
Checking GitLab Shell ...


GitLab Shell version >= 5.9.4 ? ... OK (5.9.4)
Repo base directory exists?
default... yes
Repo storage directories are symlinks?
default... no
Repo paths owned by git:root, or git:git?
default... yes
Repo paths access is drwxrws---?
default... yes
hooks directories in repos are links: ...
2/1 ... ok
2/2 ... ok
1/3 ... repository is empty
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 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? ... 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: ...
2/1 ... yes
2/2 ... yes
1/3 ... yes
Redis version >= 2.8.0? ... yes
Ruby version >= 2.3.5 ? ... yes (2.3.5)
Git version >= 2.7.3 ? ... yes (2.13.6)
Git user has default SSH configuration? ... yes
Active users: ... 2


Checking GitLab ... Finished

Possible fixes

(If you can, link to the line of code that might be responsible for the problem)