Ошибка - пытаюсь использовать Теги (django-taggit) - 'post_list_by_tag' with arguments '('',)' not found

list.html

{% block title %}Мой Блог{% endblock %}
{% block content %}
    <h1>My Blog</h1>
    {% if tag %}
        <h2>Posts tagged with "{{ tag.name }}"</h2>
    {% endif %}
    {% for post in posts %}
        <h2>
            <a href="{{ post.get_absolute_url }}">{{ post.title }}</a>
        </h2>
        <p class="tags">
            Tags:
            {% for tag in post.tags.all %}
                <a href="{% url 'blog:post_list_by_tag' tag.slug %}">
                    {{ tag.name }}
                </a>
                {% if not forloop.last %}, {% endif %}
            {% endfor %}
        </p>
        <p class="date">Published {{ post.publish }} by {{ post.author }}</p>
        {{ post.body|truncatewords:30|linebreaks }}
    {% endfor %}
    {% include "pagination.html" with page=posts %}
{% endblock %}```


urls.py

    from django.urls import path
from . import views

app_name = 'blog'
urlpatterns = [
    # post views
    path('', views.post_list, name='post_list'),

    # path('', views.PostListView.as_view(), name='post_list'),
    path('<int:year>/<int:month>/<int:day>/<slug:post>/',views.post_detail,name='post_detail'),
    path('<int:post_id>/share/', views.post_share, name='post_share'),
    path('tag/<slug:tag_slug>/', views.post_list, name='post_list_by_tag'),
]