CasAuthenticationException on google app engine

[mgallegos]

When executing Cas::authenticate() I get the following error on google app engine:

CasAuthenticationException in Sso.php line 150:
in Sso.php line 150
at Sso->authenticate()
at call_user_func_array(array(object(Sso), 'authenticate'), array()) in CasManager.php line 62
at CasManager->__call('authenticate', array()) in Facade.php line 213
at CasManager->authenticate() in Facade.php line 213
at Facade::__callStatic('authenticate', array()) in Login.php line 103
at Cas::authenticate() in Login.php line 103
at Login->getIndex()
at call_user_func_array(array(object(Login), 'getIndex'), array()) in Controller.php line 256
at Controller->callAction('getIndex', array()) in ControllerDispatcher.php line 164
at ControllerDispatcher->call(object(Login), object(Route), 'getIndex') in ControllerDispatcher.php line 112
at ControllerDispatcher->Illuminate\Routing{closure}(object(Request))
at call_user_func(object(Closure), object(Request)) in Pipeline.php line 139
at Pipeline->Illuminate\Pipeline{closure}(object(Request))
at call_user_func(object(Closure), object(Request)) in Pipeline.php line 103
at Pipeline->then(object(Closure)) in ControllerDispatcher.php line 114
at ControllerDispatcher->callWithinStack(object(Login), object(Route), object(Request), 'getIndex') in ControllerDispatcher.php line 69
at ControllerDispatcher->dispatch(object(Route), object(Request), 'App\Http\Controllers\Security\Login', 'getIndex') in Route.php line 203
at Route->runWithCustomDispatcher(object(Request)) in Route.php line 134
at Route->run(object(Request)) in Router.php line 708
at Router->Illuminate\Routing{closure}(object(Request))
at call_user_func(object(Closure), object(Request)) in Pipeline.php line 139
at Pipeline->Illuminate\Pipeline{closure}(object(Request)) in VerifyCsrfToken.php line 50
at VerifyCsrfToken->handle(object(Request), object(Closure))
at call_user_func_array(array(object(VerifyCsrfToken), 'handle'), array(object(Request), object(Closure))) in Pipeline.php line 124
at Pipeline->Illuminate\Pipeline{closure}(object(Request)) in CheckBrowser.php line 37
at CheckBrowser->handle(object(Request), object(Closure))
at call_user_func_array(array(object(CheckBrowser), 'handle'), array(object(Request), object(Closure))) in Pipeline.php line 124
at Pipeline->Illuminate\Pipeline{closure}(object(Request)) in RedirectIfAuthenticated.php line 42
at RedirectIfAuthenticated->handle(object(Request), object(Closure))
at call_user_func_array(array(object(RedirectIfAuthenticated), 'handle'), array(object(Request), object(Closure))) in Pipeline.php line 124
at Pipeline->Illuminate\Pipeline{closure}(object(Request))
at call_user_func(object(Closure), object(Request)) in Pipeline.php line 103
at Pipeline->then(object(Closure)) in Router.php line 710
at Router->runRouteWithinStack(object(Route), object(Request)) in Router.php line 675
at Router->dispatchToRoute(object(Request)) in Router.php line 635
at Router->dispatch(object(Request)) in Kernel.php line 236
at Kernel->Illuminate\Foundation\Http{closure}(object(Request))
at call_user_func(object(Closure), object(Request)) in Pipeline.php line 139
at Pipeline->Illuminate\Pipeline{closure}(object(Request)) in ShareErrorsFromSession.php line 49
at ShareErrorsFromSession->handle(object(Request), object(Closure))
at call_user_func_array(array(object(ShareErrorsFromSession), 'handle'), array(object(Request), object(Closure))) in Pipeline.php line 124
at Pipeline->Illuminate\Pipeline{closure}(object(Request)) in StartSession.php line 62
at StartSession->handle(object(Request), object(Closure))
at call_user_func_array(array(object(StartSession), 'handle'), array(object(Request), object(Closure))) in Pipeline.php line 124
at Pipeline->Illuminate\Pipeline{closure}(object(Request)) in AddQueuedCookiesToResponse.php line 37
at AddQueuedCookiesToResponse->handle(object(Request), object(Closure))
at call_user_func_array(array(object(AddQueuedCookiesToResponse), 'handle'), array(object(Request), object(Closure))) in Pipeline.php line 124
at Pipeline->Illuminate\Pipeline{closure}(object(Request)) in EncryptCookies.php line 59
at EncryptCookies->handle(object(Request), object(Closure))
at call_user_func_array(array(object(EncryptCookies), 'handle'), array(object(Request), object(Closure))) in Pipeline.php line 124
at Pipeline->Illuminate\Pipeline{closure}(object(Request)) in CheckForMaintenanceMode.php line 44
at CheckForMaintenanceMode->handle(object(Request), object(Closure))
at call_user_func_array(array(object(CheckForMaintenanceMode), 'handle'), array(object(Request), object(Closure))) in Pipeline.php line 124
at Pipeline->Illuminate\Pipeline{closure}(object(Request))
at call_user_func(object(Closure), object(Request)) in Pipeline.php line 103
at Pipeline->then(object(Closure)) in Kernel.php line 122
at Kernel->sendRequestThroughRouter(object(Request)) in Kernel.php line 87
at Kernel->handle(object(Request)) in index.php line 54

[at0dd]

Do you have a repository that I can look at? It helps to replicate the issue.