Avoid modifying frozen string in check_schema_file

This was missed when the frozen string literal pragma was added to this
file because the string is only modified when running in the context of
a full Rails app, which wasn't covered by the test suite.

1 files changed, 1 insertions, 1 deletions

diff --git a/activerecord/lib/active_record/tasks/database_tasks.rb b/activerecord/lib/active_record/tasks/database_tasks.rb
index 5c6a796857..0f3f84ca08 100644
--- a/activerecord/lib/active_record/tasks/database_tasks.rb
+++ b/activerecord/lib/active_record/tasks/database_tasks.rb
@@ -261,7 +261,7 @@ module ActiveRecord
 
       def check_schema_file(filename)
         unless File.exist?(filename)
-          message = %{#{filename} doesn't exist yet. Run `rails db:migrate` to create it, then try again.}
+          message = %{#{filename} doesn't exist yet. Run `rails db:migrate` to create it, then try again.}.dup
           message << %{ If you do not intend to use a database, you should instead alter #{Rails.root}/config/application.rb to limit the frameworks that will be loaded.} if defined?(::Rails.root)
           Kernel.abort message
         end