This issue here https://github.com/jeromemacias/Silex-Debug/issues/5 shows trace:

( ! ) Fatal error: Uncaught exception 'RuntimeException' with message 'Cannot override frozen service "data_collector.templates".' in vendor\pimple\pimple\src\Pimple\Container.php on line 76
( ! ) RuntimeException: Cannot override frozen service "data_collector.templates". in vendor\pimple\pimple\src\Pimple\Container.php on line 76
Call Stack

Time Memory Function Location

1 0.0000 233856 {main}( ) ..\index.php:0
2 0.0400 766208 Silex\Application->register( ) ..\index.php:72
3 0.0400 766288 Pimple\Container->register( ) ..\Application.php:130
4 0.0400 766360 Silex\Provider\DebugServiceProvider->register( ) ..\Container.php:273
5 0.0410 775408 Pimple\Container->offsetSet( ) ..\Container.php:36

But there is really nothing interesting on container.php line 36 https://github.com/silexphp/Pimple/blob/52f5d0969c998aa5ca7156e6ffb45eb610e235dc/src/Pimple/Container.php#L36

This should be DebugServiceProvider.php line 36 https://github.com/jeromemacias/Silex-Debug/blob/ef05e5dbfeb3a3d8a3bb5c6e5756768f92688075/DebugServiceProvider.php#L36

This is the trace with xdebug disabled:

Fatal error: Uncaught exception 'RuntimeException' with message 'Cannot override frozen service "data_collector.templates".' in vendor\pimple\pimple\src\Pimple\Container.php:76
Stack trace:
#0 vendor\jeromemacias\silex-debug\DebugServiceProvider.php(36): Pimple\Container->offsetSet('data_collector....', Array)
#1 vendor\pimple\pimple\src\Pimple\Container.php(273): Silex\Provider\DebugServiceProvider->register(Object(Silex\Application))
0000002 vendor\silex\silex\src\Silex\Application.php(130): Pimple\Container->register(Object(Silex\Provider\DebugServiceProvider), Array)
0000003 web\index.php(72): Silex\Application->register(Object(Silex\Provider\DebugServiceProvider), Array)
0000004 {main}
thrown in vendor\pimple\pimple\src\Pimple\Container.php on line 76

You can see PHP has it right and connects line 36 to the right file