<v-select
v-model="user.roles"
:items="roles"
:value_key="'id'"
:label_key="'name'"
:field_name="'roles'"
:label="'Role'"
:multiple="true"
:rules="'required'"
></v-select>
<label for="roles">Role</label>
<select name="roles" v-model="user.rolesa" v-validate="'required'" class="form-control" id="roles" multiple>
<option v-for="role in roles" :value="role.id" >{{ role.name }}</option>
</select>
<div class="invalid-feedback">{{ errors.first('roles') }}</div>