Transient failure in `qa/specs/features/ee/browser_ui/6_release/pipelines_for_merged_results_and_merge_trains_spec.rb:87` / `Unable to find visible css "[data-qa-selector=\"merge_button\"],.qa-merge-button" with text "Start merge train"`

As seen in https://ops.gitlab.net/gitlab-org/quality/staging/-/jobs/839907:

381   1) Release Pipelines for merged results and merge trains merges via a merge train
382      Failure/Error: show.merge_via_merge_train
383      
384      Capybara::ElementNotFound:
385        Unable to find visible css "[data-qa-selector=\"merge_button\"],.qa-merge-button" with text "Start merge train"
386      # /usr/local/bundle/gems/capybara-3.29.0/lib/capybara/node/finders.rb:296:in `block in synced_resolve'
387      # /usr/local/bundle/gems/capybara-3.29.0/lib/capybara/node/base.rb:83:in `synchronize'
388      # /usr/local/bundle/gems/capybara-3.29.0/lib/capybara/node/finders.rb:287:in `synced_resolve'
389      # /usr/local/bundle/gems/capybara-3.29.0/lib/capybara/node/finders.rb:52:in `find'
390      # /usr/local/bundle/gems/capybara-3.29.0/lib/capybara/session.rb:749:in `block (2 levels) in <class:Session>'
391      # /usr/local/bundle/gems/capybara-3.29.0/lib/capybara/dsl.rb:51:in `block (2 levels) in <module:DSL>'
392      # ./qa/page/base.rb:84:in `find_element'
393      # ./qa/support/page/logging.rb:45:in `find_element'
394      # ./qa/page/base.rb:119:in `click_element'
395      # ./qa/support/page/logging.rb:81:in `click_element'
396      # ./qa/ee/page/merge_request/show.rb:294:in `merge_via_merge_train'
397      # ./qa/specs/features/ee/browser_ui/6_release/pipelines_for_merged_results_and_merge_trains_spec.rb:113:in `block (4 levels) in <module:QA>'
398      # ./qa/scenario/actable.rb:16:in `perform'
399      # ./qa/specs/features/ee/browser_ui/6_release/pipelines_for_merged_results_and_merge_trains_spec.rb:106:in `block (3 levels) in <module:QA>'
400      # /usr/local/bundle/gems/rspec-retry-0.6.1/lib/rspec/retry.rb:123:in `block in run'
401      # /usr/local/bundle/gems/rspec-retry-0.6.1/lib/rspec/retry.rb:110:in `loop'
402      # /usr/local/bundle/gems/rspec-retry-0.6.1/lib/rspec/retry.rb:110:in `run'
403      # /usr/local/bundle/gems/rspec-retry-0.6.1/lib/rspec_ext/rspec_ext.rb:12:in `run_with_retry'
404      # ./spec/spec_helper.rb:68:in `block (2 levels) in <top (required)>'
405      # /usr/local/bundle/gems/rspec-retry-0.6.1/lib/rspec/retry.rb:123:in `block in run'
406      # /usr/local/bundle/gems/rspec-retry-0.6.1/lib/rspec/retry.rb:110:in `loop'
407      # /usr/local/bundle/gems/rspec-retry-0.6.1/lib/rspec/retry.rb:110:in `run'
408      # /usr/local/bundle/gems/rspec-retry-0.6.1/lib/rspec_ext/rspec_ext.rb:12:in `run_with_retry'
409      # /usr/local/bundle/gems/rspec-retry-0.6.1/lib/rspec/retry.rb:37:in `block (2 levels) in setup'
410      # ./qa/specs/runner.rb:69:in `perform'
411      # ./qa/scenario/template.rb:10:in `block in perform'
412      # ./qa/scenario/template.rb:8:in `tap'
413      # ./qa/scenario/template.rb:8:in `perform'
414      # ./qa/scenario/template.rb:33:in `perform'
415      # ./qa/scenario/template.rb:10:in `block in perform'
416      # ./qa/scenario/template.rb:8:in `tap'
417      # ./qa/scenario/template.rb:8:in `perform'
418      # ./qa/scenario/bootable.rb:28:in `launch!'

pipelines_for_merged_results_and_merge_trains_spec.rb_2020-01-14-05-32-12.042

pipelines_for_merged_results_and_merge_trains_spec.rb_2020-01-14-05-32-12.042.html