<p dir="auto">Can we please bring back the docstring comments in CrawlSpider that were removed in <a class="commit-link" data-hovercard-type="commit" data-hovercard-url="https://github.com/scrapy/scrapy/commit/e2290a5359ee80c75d8bcf8de8b6894e61fad83a/hovercard" href="https://github.com/scrapy/scrapy/commit/e2290a5359ee80c75d8bcf8de8b6894e61fad83a"><tt>e2290a5</tt></a>? The code has zero comments now. Just spent two hours pulling my hair out trying to pass extra params down the crawler. Until I found the removed docstrings in this commit that where hugely helpful :) Thanks!</p>
<p dir="auto">Hi, I ran scrapy shell and fetch('<a href="https://www.example.com" rel="nofollow">https://www.example.com</a>') then I got an error related to  "There is no current event loop in thread 'Thread-1 (start)' "</p>
<p dir="auto">the error that I get</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="2022-12-25 12:51:33 [scrapy.core.scraper] ERROR: Spider error processing &lt;GET https://www.google.com/&gt; (referer: None)
Traceback (most recent call last):
  File &quot;/home/mohsn/Documents/lrn_scrap/venv/lib/python3.10/site-packages/twisted/internet/defer.py&quot;, line 892, in _runCallbacks
    current.result = callback(  # type: ignore[misc]
  File &quot;/home/mohsn/Documents/lrn_scrap/venv/lib/python3.10/site-packages/scrapy/utils/defer.py&quot;, line 285, in f
    return deferred_from_coro(coro_f(*coro_args, **coro_kwargs))
  File &quot;/home/mohsn/Documents/lrn_scrap/venv/lib/python3.10/site-packages/scrapy/utils/defer.py&quot;, line 272, in deferred_from_coro
    event_loop = get_asyncio_event_loop_policy().get_event_loop()
  File &quot;/usr/lib/python3.10/asyncio/events.py&quot;, line 656, in get_event_loop
    raise RuntimeError('There is no current event loop in thread %r.'
RuntimeError: There is no current event loop in thread 'Thread-1 (start)'.
2022-12-25 12:51:33 [py.warnings] WARNING: /home/mohsn/Documents/lrn_scrap/venv/lib/python3.10/site-packages/twisted/internet/defer.py:892: RuntimeWarning: coroutine 'SpiderMiddlewareManager.scrape_response.&lt;locals&gt;.process_callback_output' was never awaited
  current.result = callback(  # type: ignore[misc]
"><pre class="notranslate"><code class="notranslate">2022-12-25 12:51:33 [scrapy.core.scraper] ERROR: Spider error processing &lt;GET https://www.google.com/&gt; (referer: None)
Traceback (most recent call last):
  File "/home/mohsn/Documents/lrn_scrap/venv/lib/python3.10/site-packages/twisted/internet/defer.py", line 892, in _runCallbacks
    current.result = callback(  # type: ignore[misc]
  File "/home/mohsn/Documents/lrn_scrap/venv/lib/python3.10/site-packages/scrapy/utils/defer.py", line 285, in f
    return deferred_from_coro(coro_f(*coro_args, **coro_kwargs))
  File "/home/mohsn/Documents/lrn_scrap/venv/lib/python3.10/site-packages/scrapy/utils/defer.py", line 272, in deferred_from_coro
    event_loop = get_asyncio_event_loop_policy().get_event_loop()
  File "/usr/lib/python3.10/asyncio/events.py", line 656, in get_event_loop
    raise RuntimeError('There is no current event loop in thread %r.'
RuntimeError: There is no current event loop in thread 'Thread-1 (start)'.
2022-12-25 12:51:33 [py.warnings] WARNING: /home/mohsn/Documents/lrn_scrap/venv/lib/python3.10/site-packages/twisted/internet/defer.py:892: RuntimeWarning: coroutine 'SpiderMiddlewareManager.scrape_response.&lt;locals&gt;.process_callback_output' was never awaited
  current.result = callback(  # type: ignore[misc]

</code></pre></div>
<p dir="auto">scrapy version is 2.7.1<br>
python version is 3.10.6</p>
<p dir="auto">that works for me in scrapy version 2.7.0</p>