Pipelines for Merged Results blocks merging by merge request UI

Summary

When "Merge pipelines will try to validate the post-merge result prior to merging" is enabled, it disables the merge button and doesn't run the merged refs job.

Customer reported this via support in Zendesk (internal use)

Steps to reproduce

  1. Be on GitLab v11.10.1-ee, GitLab Runner on 11.10.1, Gitaly version 1.34.0
  2. Create a new project, enable the feature
  3. Add a simple .gitlab-ci.yml file from the web UI so that master branch pipeline passes
  4. Create a new file in a new branch and create a new merge request
  5. Observe that while pipeline is running, "merge when pipeline succeeds" (MWPS) and "merge immediately" options are available and clickable
    1. When merge immediately is clicked at this point, it indicates "merge failed" (see screenshot below)
  6. When pipeline completes, nothing happens, "Merge" button is greyed out and says "You can only merge once the items above are resolved"
    1. When MWPS was clicked, the "Set by ... to be automatically merged" message remains (see screenshot below)

This happens on GDK running off master branch at ref b3fcb82d as well.

What is the expected correct behavior?

  1. According to the documentation, a pipeline should run on the merged result but this never happens.
  2. The UI should indicate that this feature is blocking the merge via UI

Relevant logs and/or screenshots

When pipeline passes, no merge refs pipeline runs:

Screenshot_2019-04-30_at_10.28.59_PM

When merge immediately is clicked while pipeline is running:

Screenshot_2019-04-30_at_10.27.56_PM

When merge when pipeline succeeds is clicked while pipeline is running and subsequently passes:

Screenshot_2019-04-30_at_10.27.12_PM

Output of checks

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

Results of GitLab environment info

Expand for output related to GitLab environment info 
System information
System:		Debian 8.11
Proxy:		no
Current User:	git
Using RVM:	no
Ruby Version:	2.5.3p105
Gem Version:	2.7.6
Bundler Version:1.17.3
Rake Version:	12.3.2
Redis Version:	3.2.12
Git Version:	2.18.1
Sidekiq Version:5.2.5
Go Version:	unknown


GitLab information
Version:	11.10.1-ee
Revision:	2cd7cedf96c
Directory:	/opt/gitlab/embedded/service/gitlab-rails
DB Adapter:	PostgreSQL
DB Version:	9.6.11
URL:		https://gitlab.weimeng.dev
HTTP Clone URL:	https://gitlab.weimeng.dev/some-group/some-project.git
SSH Clone URL:	git@gitlab.weimeng.dev:some-group/some-project.git
Elasticsearch:	yes
Geo:		no
Using LDAP:	no
Using Omniauth:	yes
Omniauth Providers:


GitLab Shell
Version:	9.0.0
Repository storage paths:
  • default: /var/opt/gitlab/git-data/repositories GitLab Shell path: /opt/gitlab/embedded/service/gitlab-shell Git: /opt/gitlab/embedded/bin/git

Results of GitLab application Check

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


Checking GitLab Shell ...


GitLab Shell: ... GitLab Shell version >= 9.0.0 ? ... OK (9.0.0)
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 ...


Gitaly: ... default ... OK


Checking Gitaly ... Finished


Checking Sidekiq ...


Sidekiq: ... Running? ... yes
Number of Sidekiq processes ... 3
Try fixing it:
sudo service gitlab stop
sudo pkill -u git -f sidekiq
sleep 10 && sudo pkill -9 -u git -f sidekiq
sudo service gitlab start
Please fix the error above and rerun the checks.


Checking Sidekiq ... Finished


Checking Incoming Email ...


Incoming Email: ... Reply by email is disabled in config/gitlab.yml


Checking Incoming Email ... Finished


Checking LDAP ...


LDAP: ... LDAP is disabled in config/gitlab.yml


Checking LDAP ... Finished


Checking GitLab App ...


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
2/3 ... yes
4/4 ... yes
8/5 ... yes
8/6 ... yes
8/7 ... yes
8/8 ... yes
8/9 ... yes
8/10 ... yes
8/11 ... yes
14/12 ... yes
15/13 ... yes
1/14 ... yes
1/15 ... yes
8/16 ... yes
1/17 ... yes
Redis version >= 2.8.0? ... yes
Ruby version >= 2.5.3 ? ... yes (2.5.3)
Git version >= 2.18.0 ? ... yes (2.18.1)
Git user has default SSH configuration? ... yes
Active users: ... 6
Elasticsearch version 5.6 - 6.x? ... yes (6.6.2)


Checking GitLab App ... Finished


Checking GitLab subtasks ... Finished

Possible fixes

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

Edited by Wei-Meng Lee