Backend: Push options are ignored for merge request pipelines

Summary

The following two features don't seem to work together

• https://docs.gitlab.com/ee/ci/merge_request_pipelines/
• https://docs.gitlab.com/ee/user/project/push_options.html#push-options-for-gitlab-cicd

I would like to use the push options

git push -o ci.variable="MY_AWESOME_VAR=something"

for merge request pipeline but it doesn't work.

Steps to reproduce

• Create a project
• Use the following .gitlab-ci.yml

include:
  - template: 'Workflows/MergeRequest-Pipelines.gitlab-ci.yml'

image: busybox:latest

show_env:
  stage: build
  script:
    - env | grep AWESOME

• Create a merge request
• Push to the merge request using git push -o ci.variable="MY_AWESOME_VAR=something"

Example Project

philipp-rs/pushoptions!1

What is the current bug behavior?

The ci.skip or ci.variable push options have no effect

What is the expected correct behavior?

Push options have an effect as per documentation