Error on generate:event:subscriber command #2406

I believe this happens when there is already a service defined. The new service/event definition does not start in a new line. But everything else is fine. Also the error could be fixed by formatting the YML file manually but the generation still has this fault. I will add the commands

dc generate:event:subscriber
Enter the module name [hello_world]:

Enter the service name [hello_world.default]:

hello_wprld.hello_listner

Class name [DefaultSubscriber]:

HelloListner

Type the event name or use keyup or keydown.
This is optional, press enter to continue

Enter event name [ ]:

kernel.request

Callback function name to handle event [kernel_request]:

onHelloRequest

Enter event name [ ]:

Do you want to load services from the container (yes/no) [no]:

Do you confirm generation? (yes/no) [yes]:

Generated or updated files
Site path: /Users/nmeegama/work_repo/d8
1 - modules/custom/hello_world/src/EventSubscriber/HelloListner.php
2 - modules/custom/hello_world/hello_world.services.yml
// cache:rebuild

Rebuilding cache(s), wait a moment please.
PHP Warning: Illegal string offset 'tags' in /Users/nmeegama/work_repo/d8/core/lib/Drupal/Core/DependencyInjection/YamlFileLoader.php on line 125

Warning: Illegal string offset 'tags' in /Users/nmeegama/work_repo/d8/core/lib/Drupal/Core/DependencyInjection/YamlFileLoader.php on line 125
PHP Fatal error: Uncaught Error: Cannot use string offset as an array in /Users/nmeegama/work_repo/d8/core/lib/Drupal/Core/DependencyInjection/YamlFileLoader.php:125
Stack trace:
#0 /Users/nmeegama/work_repo/d8/core/lib/Drupal/Core/DependencyInjection/YamlFileLoader.php(97): Drupal\Core\DependencyInjection\YamlFileLoader->parseDefinitions(Array, 'modules/custom/...')
#1 /Users/nmeegama/work_repo/d8/core/lib/Drupal/Core/DrupalKernel.php(1207): Drupal\Core\DependencyInjection\YamlFileLoader->load('modules/custom/...')
#2 /Users/nmeegama/work_repo/d8/core/lib/Drupal/Core/DrupalKernel.php(850): Drupal\Core\DrupalKernel->compileContainer()
#3 /Users/nmeegama/work_repo/d8/core/lib/Drupal/Core/DrupalKernel.php(463): Drupal\Core\DrupalKernel->initializeContainer()
#4 /Users/nmeegama/work_repo/d8/core/lib/Drupal/Core/DrupalKernel.php(703): Drupal\Core\DrupalKernel->boot()
#5 /Users/nmeegama/work_repo/d8/core/includes/utility.inc(42): Drupal\Core\DrupalKernel->prepareLegacyRequest(Object(Symfony\Component\HttpFoundation\Request))
#6 ph in /Users/nmeegama/work_repo/d8/core/lib/Drupal/Core/DependencyInjection/YamlFileLoader.php on line 125

Fatal error: Uncaught Error: Cannot use string offset as an array in /Users/nmeegama/work_repo/d8/core/lib/Drupal/Core/DependencyInjection/YamlFileLoader.php:125
Stack trace:
#0 /Users/nmeegama/work_repo/d8/core/lib/Drupal/Core/DependencyInjection/YamlFileLoader.php(97): Drupal\Core\DependencyInjection\YamlFileLoader->parseDefinitions(Array, 'modules/custom/...')
#1 /Users/nmeegama/work_repo/d8/core/lib/Drupal/Core/DrupalKernel.php(1207): Drupal\Core\DependencyInjection\YamlFileLoader->load('modules/custom/...')
#2 /Users/nmeegama/work_repo/d8/core/lib/Drupal/Core/DrupalKernel.php(850): Drupal\Core\DrupalKernel->compileContainer()
#3 /Users/nmeegama/work_repo/d8/core/lib/Drupal/Core/DrupalKernel.php(463): Drupal\Core\DrupalKernel->initializeContainer()
#4 /Users/nmeegama/work_repo/d8/core/lib/Drupal/Core/DrupalKernel.php(703): Drupal\Core\DrupalKernel->boot()
#5 /Users/nmeegama/work_repo/d8/core/includes/utility.inc(42): Drupal\Core\DrupalKernel->prepareLegacyRequest(Object(Symfony\Component\HttpFoundation\Request))
#6 ph in /Users/nmeegama/work_repo/d8/core/lib/Drupal/Core/DependencyInjection/YamlFileLoader.php on line 125

The error is in the *.service.yml file which ends up as follows (the new event generated is in bold)
parameters:
hello_world.hello_cache: true
services:
hello_world.url_param_reader:
class: Drupal\hello_world\UtilityServices\URLParamReader
arguments:
- '@keyvalue'
- %hello_world.hello_cache% hello_wprld.hello_listner:
class: Drupal\hello_world\EventSubscriber\HelloListner
arguments: []
tags:
- { name: event_subscriber }

The error is gone once we correct the YML file manually