sentry-php: [1.x] PHP Fatal error: Uncaught ErrorException: Undefined index: function in /lib/Raven/Stacktrace.php:89

Guess this is PHP7 problem

problem is with the code 'function' => $nextframe['function'],

$nextframe doesn’t necessary contain function index, it can be for example

array (
  'file' => '/vagrant/dev/admin/vendor/composer/ClassLoader.php',
  'line' => 412,
  'include_filename' => '/vagrant/dev/admin/app/SaaS/Admin/Models/User.php',
  'args' => 
  array (
  ),
)

Addressing undefined index leads to error posted in subject.