Skip variables duplicates validator if variable is already a duplicate

app/models/group.rb

@@ -37,7 +37,6 @@ class Group < Namespace
   validate :visibility_level_allowed_by_sub_groups
   validate :visibility_level_allowed_by_parent
   validates :variables, variable_duplicates: true
-  validates_associated :variables, if: proc { |group| group.errors[:variables].nil? }
 
   validates :two_factor_grace_period, presence: true, numericality: { greater_than_or_equal_to: 0 }
 

app/validators/variable_duplicates_validator.rb

@@ -5,6 +5,8 @@
 # - Use `validates :xxx, uniqueness: { scope: :xxx_id }` in a child model
 class VariableDuplicatesValidator < ActiveModel::EachValidator
   def validate_each(record, attribute, value)
+    return if record.errors.include?(:"#{attribute}.key")
+
     if options[:scope]
       scoped = value.group_by do |variable|
         Array(options[:scope]).map { |attr| variable.send(attr) } # rubocop:disable GitlabSecurity/PublicSend

spec/support/features/variable_list_shared_examples.rb

@@ -261,6 +261,8 @@ shared_examples 'variable list' do
     click_button('Save variables')
     wait_for_requests
 
+    expect(all('.js-ci-variable-list-section .js-ci-variable-error-box ul li').count).to eq(1)
+
     # We check the first row because it re-sorts to alphabetical order on refresh
     page.within('.js-ci-variable-list-section') do
       expect(find('.js-ci-variable-error-box')).to have_content(/Validation failed Variables have duplicate values \(.+\)/)