AppGeneratorTest fails because `Could not find gem 'kamal' in locally installed gems.` about rails

[yahonda]

• Removing the quietly block

$ git diff
diff --git a/railties/test/generators/app_generator_test.rb b/railties/test/generators/app_generator_test.rb
index 21a1587c74..7158b1232e 100644
--- a/railties/test/generators/app_generator_test.rb
+++ b/railties/test/generators/app_generator_test.rb
@@ -1506,7 +1506,7 @@ def run_app_update(app_root = destination_root, flags: "--force")
         gemfile_contents.sub!(/^(gem "rails").*/, "\\1, path: #{File.expand_path("../../..", __dir__).inspect}")
         File.write("Gemfile", gemfile_contents)

-        quietly { system({ "BUNDLE_GEMFILE" => "Gemfile" }, "bin/rails app:update #{flags}", exception: true) }
+        system({ "BUNDLE_GEMFILE" => "Gemfile" }, "bin/rails app:update #{flags}", exception: true)
       end
     end

$

• Run the same test shows the actual error message "Could not find gem 'kamal' in locally installed gems."

$ bin/test test/generators/app_generator_test.rb:434
Run options: --seed 23390

# Running:

Could not find gem 'kamal' in locally installed gems.
Run `bundle install` to install missing gems.
E

Error:
AppGeneratorTest#test_app_update_does_not_change_app_name_when_app_name_is_hyphenated_name:
RuntimeError: Command failed with exit 7: bin/rails
    test/generators/app_generator_test.rb:1509:in `system'
    test/generators/app_generator_test.rb:1509:in `block in run_app_update'
    test/generators/app_generator_test.rb:1504:in `chdir'
    test/generators/app_generator_test.rb:1504:in `run_app_update'
    test/generators/app_generator_test.rb:448:in `test_app_update_does_not_change_app_name_when_app_name_is_hyphenated_name'


bin/test test/generators/app_generator_test.rb:434



Finished in 0.794015s, 1.2594 runs/s, 15.1131 assertions/s.
1 runs, 12 assertions, 0 failures, 1 errors, 0 skips
$