<!--IssueSummary start--> <details> <summary> Everyone can contribute. [Help move this issue forward](https://handbook.gitlab.com/handbook/marketing/developer-relations/contributor-success/community-contributors-workflows/#contributor-links) while earning points, leveling up and collecting rewards. </summary> - [Close this issue](https://contributors.gitlab.com/manage-issue?action=close&projectId=278964&issueIid=537269) </details> <!--IssueSummary end--> <!--- Please read this! Before opening a new issue, make sure to search for keywords in the issues filtered by the "regression" or "type::bug" label: - https://gitlab.com/gitlab-org/gitlab/issues?label_name%5B%5D=regression - https://gitlab.com/gitlab-org/gitlab/issues?label_name%5B%5D=type::bug and verify the issue you're about to submit isn't a duplicate. ---> ### Summary When opening an MR which doesn't contain merge conflicts, and using the `/rebase` in the MR description, an exception is thrown. ### Steps to reproduce 1. Create a project 2. Introduce a change, and commit into a new branch 3. Create an MR from new branch into default branch 4. Use `/rebase` anywhere in the Description ### Example Project https://gitlab.com/customer-issue-reproduction/zd-622067 ### What is the current *bug* behavior? A user facing exception is thrown:  01JSHNQ4PJEF2TQNZ4FKK3V0ND ### What is the expected *correct* behavior? Either: 1. `/rebase` is ignored or, 2. a user-friendly error is thrown. ### Workaround Don't use `/rebase` in MR descriptions. ### Relevant logs and/or screenshots <details><summary>Log event</summary> ```json { "correlation_id": "01JSHNQ4PJEF2TQNZ4FKK3V0ND", "username": "niklasjanz", "meta.caller_id": "Projects::MergeRequests::CreationsController#create", "user_id": 7538998, "meta.feature_category": "code_review_workflow", "meta.user": "niklasjanz", "meta.project": "customer-issue-reproduction/zd-622067", "cf_ray": "934e8a2420a18fe8-IAD", "status": 500, "cf_ipcountry": "DE", "exception.backtrace": [ "app/services/issuable_base_service.rb:201:in `create'", "app/services/merge_requests/base_service.rb:149:in `create'", "app/services/merge_requests/create_service.rb:16:in `execute'", "app/controllers/projects/merge_requests/creations_controller.rb:38:in `create'", "lib/gitlab/ip_address_state.rb:11:in `with'", "ee/app/controllers/ee/application_controller.rb:45:in `set_current_ip_address'", "app/controllers/application_controller.rb:487:in `set_current_admin'", "lib/gitlab/session.rb:11:in `with_session'", "app/controllers/application_controller.rb:478:in `set_session_storage'", "lib/gitlab/i18n.rb:114:in `with_locale'", "lib/gitlab/i18n.rb:120:in `with_user_locale'", "app/controllers/application_controller.rb:469:in `set_locale'", "app/controllers/application_controller.rb:462:in `set_current_context'", "lib/gitlab/middleware/action_controller_static_context.rb:23:in `call'", "ee/lib/omni_auth/strategies/group_saml.rb:41:in `other_phase'", "lib/gitlab/metrics/elasticsearch_rack_middleware.rb:16:in `call'", "lib/gitlab/middleware/sidekiq_shard_awareness_validation.rb:20:in `block in call'", "lib/gitlab/sidekiq_sharding/validator.rb:42:in `enabled'", "lib/gitlab/middleware/sidekiq_shard_awareness_validation.rb:20:in `call'", "lib/gitlab/middleware/memory_report.rb:13:in `call'", "lib/gitlab/middleware/speedscope.rb:13:in `call'", "lib/gitlab/database/load_balancing/rack_middleware.rb:23:in `call'", "lib/gitlab/middleware/rails_queue_duration.rb:33:in `call'", "lib/gitlab/etag_caching/middleware.rb:21:in `call'", "lib/gitlab/metrics/rack_middleware.rb:16:in `block in call'", "lib/gitlab/metrics/web_transaction.rb:46:in `run'", "lib/gitlab/metrics/rack_middleware.rb:16:in `call'", "lib/gitlab/middleware/go.rb:21:in `call'", "lib/gitlab/middleware/query_analyzer.rb:11:in `block in call'", "lib/gitlab/database/query_analyzer.rb:83:in `within'", "lib/gitlab/middleware/query_analyzer.rb:11:in `call'", "lib/ci/job_token/middleware.rb:11:in `call'", "lib/gitlab/middleware/multipart.rb:173:in `call'", "lib/gitlab/middleware/read_only/controller.rb:50:in `call'", "lib/gitlab/middleware/read_only.rb:18:in `call'", "lib/gitlab/middleware/unauthenticated_session_expiry.rb:18:in `call'", "lib/gitlab/middleware/secure_headers.rb:11:in `call'", "lib/gitlab/middleware/same_site_cookies.rb:27:in `call'", "lib/gitlab/middleware/path_traversal_check.rb:40:in `call'", "lib/gitlab/middleware/handle_malformed_strings.rb:21:in `call'", "lib/gitlab/middleware/basic_health_check.rb:25:in `call'", "lib/gitlab/middleware/handle_ip_spoof_attack_error.rb:25:in `call'", "lib/gitlab/middleware/request_context.rb:15:in `call'", "lib/gitlab/middleware/webhook_recursion_detection.rb:15:in `call'", "config/initializers/fix_local_cache_middleware.rb:11:in `call'", "lib/gitlab/middleware/compressed_json.rb:44:in `call'", "lib/gitlab/middleware/rack_multipart_tempfile_factory.rb:19:in `call'", "lib/gitlab/middleware/sidekiq_web_static.rb:20:in `call'", "lib/gitlab/metrics/requests_rack_middleware.rb:83:in `call'", "lib/gitlab/middleware/release_env.rb:12:in `call'" ], "format": "html", "method": "POST", "shard": "default", "meta.root_namespace": "customer-issue-reproduction", "params": [ { "key": "authenticity_token", "value": "[FILTERED]" }, { "key": "merge_request", "value": "{\"title\"=>\"[FILTERED]\", \"description\"=>\"[FILTERED]\", \"assignee_ids\"=>[\"0\"], \"reviewer_ids\"=>[\"0\"], \"milestone_id\"=>\"\", \"merge_after\"=>\"\", \"force_remove_source_branch\"=>\"1\", \"squash\"=>\"0\", \"lock_version\"=>\"0\", \"source_project_id\"=>\"69227657\", \"source_branch\"=>\"niklasjanz-main-patch-81781\", \"target_project_id\"=>\"69227657\", \"target_branch\"=>\"main\"}" }, { "value": "acf5066599cce24771381e80e828331024296ec8", "key": "merge_request_diff_head_sha" }, { "key": "namespace_id", "value": "customer-issue-reproduction" }, { "key": "project_id", "value": "zd-622067" } ], "redis_shared_state_calls": 4, "exception.class": "ActiveModel::UnknownAttributeError", "controller": "Projects::MergeRequests::CreationsController", "type": "web", "meta.http_router_rule_action": "proxy", "subcomponent": "production_json", "exception.message": "unknown attribute 'rebase' for MergeRequest.", "path": "/customer-issue-reproduction/zd-622067/-/merge_requests", "action": "create", "time": "2025-04-23T15:54:28.100Z", "meta.user_id": 7538998, "stage": "cny", "tier": "sv" } ``` </details> ### Output of checks <!-- If you are reporting a bug on GitLab.com, uncomment below --> This bug happens on GitLab.com <!-- and uncomment below if you have /label privileges --> <!-- /label ~"reproduced on GitLab.com" --> <!-- or follow up with an issue comment of `@gitlab-bot label ~"reproduced on GitLab.com"` if you do not --> #### Results of GitLab environment info <!-- Input any relevant GitLab environment information if needed. --> <details> <summary>Expand for output related to GitLab environment info</summary> <pre> (For installations with omnibus-gitlab package run and paste the output of: `sudo gitlab-rake gitlab:env:info`) (For installations from source run and paste the output of: `sudo -u git -H bundle exec rake gitlab:env:info RAILS_ENV=production`) </pre> </details> #### Results of GitLab application Check <!-- Input any relevant GitLab application check information if needed. --> <details> <summary>Expand for output related to the GitLab application check</summary> <pre> (For installations with omnibus-gitlab package run and paste the output of: `sudo gitlab-rake gitlab:check SANITIZE=true`) (For installations from source run and paste the output of: `sudo -u git -H bundle exec rake gitlab:check RAILS_ENV=production SANITIZE=true`) (we will only investigate if the tests are passing) </pre> </details> ### Possible fixes <!-- If you can, link to the line of code that might be responsible for the problem. --> <!-- If you don't have /label privileges, follow up with an issue comment of `@gitlab-bot label ~"type::bug"` -->