Directive inside $modal window throws "undefined is not a function" - angularjs

Question

Using ui-bootstrap I have a really simple custom directive that lists alerts at the top of the page. On normal pages it works like a champ. When I use my directive inside a $modal popup I get "undefined is not a function" at ngRepeatAction.
The directive I have behind the modal on the main page still works. I can see it behind the modal. It's just the one in the modal popup that breaks. What am I doing wrong?
Modal open code:
$modal.open({
templateUrl: 'partials/main/servers/serverAuths/edit.html',
controller: function($scope, $modalInstance) {
$scope.auth = angular.copy(auth);
$scope.auth.password = null;
$scope.saveAuth = function() {
Auths.editAuth($scope.auth).then(
function(resp) {
if (resp.rc===0) {
Alerts.addAlert('success', 'Auth `'+$scope.auth.name+'` saved.');
_.extend(auth, $scope.auth);
$modalInstance.close();
} else {
Alerts.addAlert('danger', 'Auth `'+$scope.auth.name+'` could not be saved. ' + resp.message, 'serverAuths');
}
}
);
};
$scope.resetAuth = function() {
$modalInstance.close();
};
}
}).result.then(
function() {
Auths.getAuthList().then(
function(resp) {
$scope.auths = resp;
}
);
}
);
Directive template:
<div class="alert-wrapper alert-{{ alert.type }}"
ng-repeat="alert in alerts"
ng-class="{ 'relative':relative }">
<div class="container">
<div alert type="alert.type" close="closeAlert($index)">{{alert.msg}}</div>
</div>
</div>
Directive code:
angular.module('app')
.directive('appAlerts', function() {
return {
restrict: 'A',
replace: true,
scope: {
watchForm: '=',
relative: '#'
},
templateUrl: 'partials/directives/appAlerts.html',
controller: function($scope, Alerts) {
$scope.closeAlert = function(idx) { Alerts.closeAlert(idx); };
$scope.alerts = Alerts.getAlerts();
}
};
});
Alerts Factory:
angular.module('app').factory('Alerts', function($timeout) {
var alerts = [];
function timeoutAlert(a) {
$timeout(function() {
a.splice(0, 1);
}, 2500);
}
var addAlert = function(type, msg) {
alerts.push({type:type, msg:msg});
timeoutAlert(alerts);
};
var closeAlert = function(index) {
alerts.splice(index, 1);
};
var getAlerts = function() {
return alerts;
};
var killAlert = function(msg) {
var alert = _.where(alerts, {msg:msg});
var idx = _.indexOf(alerts, alert[0]);
if (idx > -1) {
closeAlert(idx);
}
};
return {
addAlert:addAlert,
closeAlert:closeAlert,
getAlerts:getAlerts,
killAlert:killAlert
};
});