<h1 dir="auto">Checklist</h1>

<ul class="contains-task-list">
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have verified that the issue exists against the <code class="notranslate">master</code> branch of Celery.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> This has already been asked to the <a href="https://groups.google.com/forum/#!forum/celery-users" rel="nofollow">discussion group</a> first.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have read the relevant section in the<br>
<a href="http://docs.celeryproject.org/en/latest/contributing.html#other-bugs" rel="nofollow">contribution guide</a><br>
on reporting bugs.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have checked the <a href="https://github.com/celery/celery/issues?q=is%3Aissue+label%3A%22Issue+Type%3A+Bug+Report%22+-label%3A%22Category%3A+Documentation%22">issues list</a><br>
for similar or identical bug reports.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have checked the <a href="https://github.com/celery/celery/pulls?q=is%3Apr+label%3A%22PR+Type%3A+Bugfix%22+-label%3A%22Category%3A+Documentation%22">pull requests list</a><br>
for existing proposed fixes.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have checked the <a href="https://github.com/celery/celery/commits/master">commit log</a><br>
to find out if the bug was already fixed in the master branch.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have included all related issues and possible duplicate issues<br>
in this issue (If there are none, check this box anyway).</li>
</ul>
<h2 dir="auto">Mandatory Debugging Information</h2>
<ul class="contains-task-list">
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have included the output of <code class="notranslate">celery -A proj report</code> in the issue.<br>
(if you are not able to do this, then at least specify the Celery<br>
version affected).</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have verified that the issue exists against the <code class="notranslate">master</code> branch of Celery.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have included the contents of <code class="notranslate">pip freeze</code> in the issue.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have included all the versions of all the external dependencies required<br>
to reproduce this bug.</li>
</ul>
<h2 dir="auto">Optional Debugging Information</h2>

<ul class="contains-task-list">
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have tried reproducing the issue on more than one Python version<br>
and/or implementation.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have tried reproducing the issue on more than one message broker and/or<br>
result backend.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have tried reproducing the issue on more than one version of the message<br>
broker and/or result backend.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have tried reproducing the issue on more than one operating system.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have tried reproducing the issue on more than one workers pool.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have tried reproducing the issue with autoscaling, retries,<br>
ETA/Countdown &amp; rate limits disabled.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have tried reproducing the issue after downgrading<br>
and/or upgrading Celery and its dependencies.</li>
</ul>
<h2 dir="auto">Related Issues and Possible Duplicates</h2>

<h4 dir="auto">Related Issues</h4>
<ul dir="auto">
<li>None</li>
</ul>
<h4 dir="auto">Possible Duplicates</h4>
<ul dir="auto">
<li>None</li>
</ul>
<h2 dir="auto">Environment &amp; Settings</h2>

<p dir="auto"><strong>Celery version</strong>:  <code class="notranslate">5.1.0b1 (singularity)</code></p>

<details>
<summary><b><code class="notranslate">celery report</code> Output:</b></summary>
<p dir="auto">
</p><div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="software -&gt; celery:5.1.0b1 (singularity) kombu:5.1.0b1 py:3.8.5
            billiard:3.6.4.0 py-amqp:5.0.6
platform -&gt; system:Linux arch:64bit, ELF
            kernel version:5.8.0-48-generic imp:CPython
loader   -&gt; celery.loaders.app.AppLoader
settings -&gt; transport:amqp results:redis://localhost/

broker_url: 'amqp://guest:********@localhost:5672//'
result_backend: 'redis://localhost/'
deprecated_settings: None"><pre class="notranslate"><code class="notranslate">software -&gt; celery:5.1.0b1 (singularity) kombu:5.1.0b1 py:3.8.5
            billiard:3.6.4.0 py-amqp:5.0.6
platform -&gt; system:Linux arch:64bit, ELF
            kernel version:5.8.0-48-generic imp:CPython
loader   -&gt; celery.loaders.app.AppLoader
settings -&gt; transport:amqp results:redis://localhost/

broker_url: 'amqp://guest:********@localhost:5672//'
result_backend: 'redis://localhost/'
deprecated_settings: None
</code></pre></div>
<p dir="auto"></p>
</details>
<h1 dir="auto">Steps to Reproduce</h1>
<h2 dir="auto">Required Dependencies</h2>

<ul dir="auto">
<li><strong>Minimal Python Version</strong>: N/A or Unknown</li>
<li><strong>Minimal Celery Version</strong>: N/A or Unknown</li>
<li><strong>Minimal Kombu Version</strong>: N/A or Unknown</li>
<li><strong>Minimal Broker Version</strong>: N/A or Unknown</li>
<li><strong>Minimal Result Backend Version</strong>: N/A or Unknown</li>
<li><strong>Minimal OS and/or Kernel Version</strong>: N/A or Unknown</li>
<li><strong>Minimal Broker Client Version</strong>: N/A or Unknown</li>
<li><strong>Minimal Result Backend Client Version</strong>: N/A or Unknown</li>
</ul>
<h3 dir="auto">Python Packages</h3>

<details>
<summary><b><code class="notranslate">pip freeze</code> Output:</b></summary>
<p dir="auto">
</p><div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content=""><pre class="notranslate"><code class="notranslate"></code></pre></div>
<p dir="auto"></p>
</details>
<h3 dir="auto">Other Dependencies</h3>

<details>
<p dir="auto">
N/A
</p>
</details>
<h2 dir="auto">Minimally Reproducible Test Case</h2>

<details>
<p dir="auto">
</p><div class="highlight highlight-source-python notranslate position-relative overflow-auto" dir="auto" data-snippet-clipboard-copy-content="import celery

app = celery.Celery(
    broker='amqp://localhost',
    backend='redis://localhost',
)


@app.task
def task_a(number):
    print(f'Task A: {number}')
    return number


@app.task
def task_b(number):
    print(f'Task B: {number}')
    return number


@app.task
def task_c(number):
    print(f'Task C: {number}')


if __name__ == '__main__':
    celery.chord(
      (celery.chain(task_a.s(i), task_b.s()))
      for i in range(3)
    )(task_c.s())  # yapf: disable

    app.start()"><pre class="notranslate"><span class="pl-k">import</span> <span class="pl-s1">celery</span>

<span class="pl-s1">app</span> <span class="pl-c1">=</span> <span class="pl-s1">celery</span>.<span class="pl-v">Celery</span>(
    <span class="pl-s1">broker</span><span class="pl-c1">=</span><span class="pl-s">'amqp://localhost'</span>,
    <span class="pl-s1">backend</span><span class="pl-c1">=</span><span class="pl-s">'redis://localhost'</span>,
)


<span class="pl-en">@<span class="pl-s1">app</span>.<span class="pl-s1">task</span></span>
<span class="pl-k">def</span> <span class="pl-en">task_a</span>(<span class="pl-s1">number</span>):
    <span class="pl-en">print</span>(<span class="pl-s">f'Task A: <span class="pl-s1"><span class="pl-kos">{</span><span class="pl-s1">number</span><span class="pl-kos">}</span></span>'</span>)
    <span class="pl-k">return</span> <span class="pl-s1">number</span>


<span class="pl-en">@<span class="pl-s1">app</span>.<span class="pl-s1">task</span></span>
<span class="pl-k">def</span> <span class="pl-en">task_b</span>(<span class="pl-s1">number</span>):
    <span class="pl-en">print</span>(<span class="pl-s">f'Task B: <span class="pl-s1"><span class="pl-kos">{</span><span class="pl-s1">number</span><span class="pl-kos">}</span></span>'</span>)
    <span class="pl-k">return</span> <span class="pl-s1">number</span>


<span class="pl-en">@<span class="pl-s1">app</span>.<span class="pl-s1">task</span></span>
<span class="pl-k">def</span> <span class="pl-en">task_c</span>(<span class="pl-s1">number</span>):
    <span class="pl-en">print</span>(<span class="pl-s">f'Task C: <span class="pl-s1"><span class="pl-kos">{</span><span class="pl-s1">number</span><span class="pl-kos">}</span></span>'</span>)


<span class="pl-k">if</span> <span class="pl-s1">__name__</span> <span class="pl-c1">==</span> <span class="pl-s">'__main__'</span>:
    <span class="pl-s1">celery</span>.<span class="pl-en">chord</span>(
      (<span class="pl-s1">celery</span>.<span class="pl-en">chain</span>(<span class="pl-s1">task_a</span>.<span class="pl-en">s</span>(<span class="pl-s1">i</span>), <span class="pl-s1">task_b</span>.<span class="pl-en">s</span>()))
      <span class="pl-k">for</span> <span class="pl-s1">i</span> <span class="pl-c1">in</span> <span class="pl-en">range</span>(<span class="pl-c1">3</span>)
    )(<span class="pl-s1">task_c</span>.<span class="pl-en">s</span>())  <span class="pl-c"># yapf: disable</span>

    <span class="pl-s1">app</span>.<span class="pl-en">start</span>()</pre></div>
<p dir="auto"></p>
</details>
<h1 dir="auto">Expected Behavior</h1>

<p dir="auto">Expected output:</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="[2021-04-11 16:44:51,364: WARNING/ForkPoolWorker-15] Task A: 0
[2021-04-11 16:44:51,364: WARNING/ForkPoolWorker-16] Task A: 1
[2021-04-11 16:44:51,364: WARNING/ForkPoolWorker-1] Task A: 2
[2021-04-11 16:44:51,387: WARNING/ForkPoolWorker-4] Task B: 2
[2021-04-11 16:44:51,387: WARNING/ForkPoolWorker-3] Task B: 0
[2021-04-11 16:44:51,387: WARNING/ForkPoolWorker-2] Task B: 1
[2021-04-11 16:44:51,413: WARNING/ForkPoolWorker-15] Task C: [0, 1, 2]"><pre class="notranslate"><code class="notranslate">[2021-04-11 16:44:51,364: WARNING/ForkPoolWorker-15] Task A: 0
[2021-04-11 16:44:51,364: WARNING/ForkPoolWorker-16] Task A: 1
[2021-04-11 16:44:51,364: WARNING/ForkPoolWorker-1] Task A: 2
[2021-04-11 16:44:51,387: WARNING/ForkPoolWorker-4] Task B: 2
[2021-04-11 16:44:51,387: WARNING/ForkPoolWorker-3] Task B: 0
[2021-04-11 16:44:51,387: WARNING/ForkPoolWorker-2] Task B: 1
[2021-04-11 16:44:51,413: WARNING/ForkPoolWorker-15] Task C: [0, 1, 2]
</code></pre></div>
<p dir="auto">On <code class="notranslate">celery==5.0.5</code> it works fine</p>
<h1 dir="auto">Actual Behavior</h1>

<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="[2021-04-11 16:33:24,583: WARNING/ForkPoolWorker-15] Task A: 0
[2021-04-11 16:33:24,583: WARNING/ForkPoolWorker-1] Task A: 2
[2021-04-11 16:33:24,583: WARNING/ForkPoolWorker-16] Task A: 1
[2021-04-11 16:33:24,608: WARNING/ForkPoolWorker-4] Task B: 2
[2021-04-11 16:33:24,608: WARNING/ForkPoolWorker-2] Task B: 0
[2021-04-11 16:33:24,608: WARNING/ForkPoolWorker-3] Task B: 1"><pre class="notranslate"><code class="notranslate">[2021-04-11 16:33:24,583: WARNING/ForkPoolWorker-15] Task A: 0
[2021-04-11 16:33:24,583: WARNING/ForkPoolWorker-1] Task A: 2
[2021-04-11 16:33:24,583: WARNING/ForkPoolWorker-16] Task A: 1
[2021-04-11 16:33:24,608: WARNING/ForkPoolWorker-4] Task B: 2
[2021-04-11 16:33:24,608: WARNING/ForkPoolWorker-2] Task B: 0
[2021-04-11 16:33:24,608: WARNING/ForkPoolWorker-3] Task B: 1
</code></pre></div>
<h1 dir="auto">Checklist</h1>

<ul class="contains-task-list">
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have verified that the issue exists against the <code class="notranslate">master</code> branch of Celery.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> This has already been asked to the <a href="https://groups.google.com/forum/#!forum/celery-users" rel="nofollow">discussion group</a> first.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have read the relevant section in the<br>
<a href="http://docs.celeryproject.org/en/latest/contributing.html#other-bugs" rel="nofollow">contribution guide</a><br>
on reporting bugs.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have checked the <a href="https://github.com/celery/celery/issues?q=is%3Aissue+label%3A%22Issue+Type%3A+Bug+Report%22+-label%3A%22Category%3A+Documentation%22">issues list</a><br>
for similar or identical bug reports.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have checked the <a href="https://github.com/celery/celery/pulls?q=is%3Apr+label%3A%22PR+Type%3A+Bugfix%22+-label%3A%22Category%3A+Documentation%22">pull requests list</a><br>
for existing proposed fixes.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have checked the <a href="https://github.com/celery/celery/commits/master">commit log</a><br>
to find out if the bug was already fixed in the master branch.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have included all related issues and possible duplicate issues<br>
in this issue (If there are none, check this box anyway).</li>
</ul>
<h2 dir="auto">Mandatory Debugging Information</h2>
<ul class="contains-task-list">
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have included the output of <code class="notranslate">celery -A proj report</code> in the issue.<br>
(if you are not able to do this, then at least specify the Celery<br>
version affected).</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have verified that the issue exists against the <code class="notranslate">master</code> branch of Celery.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have included the contents of <code class="notranslate">pip freeze</code> in the issue.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have included all the versions of all the external dependencies required<br>
to reproduce this bug.</li>
</ul>
<h2 dir="auto">Optional Debugging Information</h2>

<ul class="contains-task-list">
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have tried reproducing the issue on more than one Python version<br>
and/or implementation.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have tried reproducing the issue on more than one message broker and/or<br>
result backend.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have tried reproducing the issue on more than one version of the message<br>
broker and/or result backend.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have tried reproducing the issue on more than one operating system.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have tried reproducing the issue on more than one workers pool.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have tried reproducing the issue with autoscaling, retries,<br>
ETA/Countdown &amp; rate limits disabled.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have tried reproducing the issue after downgrading<br>
and/or upgrading Celery and its dependencies.</li>
</ul>
<h2 dir="auto">Related Issues and Possible Duplicates</h2>

<h4 dir="auto">Related Issues</h4>
<ul dir="auto">
<li>None</li>
</ul>
<h4 dir="auto">Possible Duplicates</h4>
<ul dir="auto">
<li>None</li>
</ul>
<h2 dir="auto">Environment &amp; Settings</h2>

<p dir="auto"><strong>Celery version</strong>: 5.05 and master (<a class="commit-link" data-hovercard-type="commit" data-hovercard-url="https://github.com/celery/celery/commit/2411504f4164ac9acfa20007038d37591c6f57e5/hovercard" href="https://github.com/celery/celery/commit/2411504f4164ac9acfa20007038d37591c6f57e5"><tt>2411504</tt></a>)</p>

<details>
<summary><b><code class="notranslate">celery report</code> Output:</b></summary>
<p dir="auto">
</p><div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="software -&gt; celery:5.1.0b2 (singularity) kombu:5.1.0b1 py:3.9.5
            billiard:3.6.4.0 py-amqp:5.0.6
platform -&gt; system:Darwin arch:64bit
            kernel version:20.4.0 imp:CPython
loader   -&gt; celery.loaders.app.AppLoader
settings -&gt; transport:amqp results:disabled

deprecated_settings: None"><pre class="notranslate"><code class="notranslate">software -&gt; celery:5.1.0b2 (singularity) kombu:5.1.0b1 py:3.9.5
            billiard:3.6.4.0 py-amqp:5.0.6
platform -&gt; system:Darwin arch:64bit
            kernel version:20.4.0 imp:CPython
loader   -&gt; celery.loaders.app.AppLoader
settings -&gt; transport:amqp results:disabled

deprecated_settings: None
</code></pre></div>
<p dir="auto"></p>
</details>
<h1 dir="auto">Steps to Reproduce</h1>
<h2 dir="auto">Required Dependencies</h2>

<ul dir="auto">
<li><strong>Minimal Python Version</strong>: Unknown, tested on 3.9</li>
<li><strong>Minimal Celery Version</strong>: Unknown, tested on 5.05 and master</li>
<li><strong>Minimal Kombu Version</strong>: N/A</li>
<li><strong>Minimal Broker Version</strong>: N/A</li>
<li><strong>Minimal Result Backend Version</strong>: N/A</li>
<li><strong>Minimal OS and/or Kernel Version</strong>: N/A</li>
<li><strong>Minimal Broker Client Version</strong>: N/A</li>
<li><strong>Minimal Result Backend Client Version</strong>: N/A</li>
</ul>
<h3 dir="auto">Python Packages</h3>

<details>
<summary><b><code class="notranslate">pip freeze</code> Output:</b></summary>
<p dir="auto">
</p><div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="amqp==5.0.6
billiard==3.6.4.0
celery @ git+https://github.com/celery/celery.git@2411504f4164ac9acfa20007038d37591c6f57e5
click==7.1.2
click-didyoumean==0.0.3
click-plugins==1.1.1
click-repl==0.1.6
kombu==5.1.0b1
prompt-toolkit==3.0.18
pytz==2021.1
six==1.16.0
vine==5.0.0
wcwidth==0.2.5"><pre class="notranslate"><code class="notranslate">amqp==5.0.6
billiard==3.6.4.0
celery @ git+https://github.com/celery/celery.git@2411504f4164ac9acfa20007038d37591c6f57e5
click==7.1.2
click-didyoumean==0.0.3
click-plugins==1.1.1
click-repl==0.1.6
kombu==5.1.0b1
prompt-toolkit==3.0.18
pytz==2021.1
six==1.16.0
vine==5.0.0
wcwidth==0.2.5
</code></pre></div>
<p dir="auto"></p>
</details>
<h3 dir="auto">Other Dependencies</h3>

<details>
<p dir="auto">
N/A
</p>
</details>
<h2 dir="auto">Minimally Reproducible Test Case</h2>

<details>
<p dir="auto">
</p><p dir="auto"><code class="notranslate">app.py</code>:</p>
<div class="highlight highlight-source-python notranslate position-relative overflow-auto" dir="auto" data-snippet-clipboard-copy-content="import celery

app = celery.Celery()"><pre class="notranslate"><span class="pl-k">import</span> <span class="pl-s1">celery</span>

<span class="pl-s1">app</span> <span class="pl-c1">=</span> <span class="pl-s1">celery</span>.<span class="pl-v">Celery</span>()</pre></div>
<p dir="auto"><code class="notranslate">camera.py</code>:</p>
<div class="highlight highlight-source-python notranslate position-relative overflow-auto" dir="auto" data-snippet-clipboard-copy-content="from celery.events.snapshot import Polaroid

class Camera(Polaroid):
    def on_shutter(self, _):
        print(&quot;Hello!&quot;)"><pre class="notranslate"><span class="pl-k">from</span> <span class="pl-s1">celery</span>.<span class="pl-s1">events</span>.<span class="pl-s1">snapshot</span> <span class="pl-k">import</span> <span class="pl-v">Polaroid</span>

<span class="pl-k">class</span> <span class="pl-v">Camera</span>(<span class="pl-v">Polaroid</span>):
    <span class="pl-k">def</span> <span class="pl-en">on_shutter</span>(<span class="pl-s1">self</span>, <span class="pl-s1">_</span>):
        <span class="pl-en">print</span>(<span class="pl-s">"Hello!"</span>)</pre></div>
<p dir="auto"></p>
</details>
<h1 dir="auto">Expected Behavior</h1>

<p dir="auto">The following command should (attempt to) start the event camera:</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="$ celery -A app events -c camera
...
ModuleNotFoundError: No module named 'camera'"><pre class="notranslate"><code class="notranslate">$ celery -A app events -c camera
...
ModuleNotFoundError: No module named 'camera'
</code></pre></div>
<p dir="auto">(The bug is independent of whether the module <code class="notranslate">camera</code> exists.)</p>
<h1 dir="auto">Actual Behavior</h1>

<p dir="auto">A backtrace is produced:</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="Traceback (most recent call last):
  File &quot;/Users/user/Desktop/tmp/venv/bin/celery&quot;, line 8, in &lt;module&gt;
    sys.exit(main())
  File &quot;/Users/user/Desktop/tmp/venv/lib/python3.9/site-packages/celery/__main__.py&quot;, line 15, in main
    sys.exit(_main())
  File &quot;/Users/user/Desktop/tmp/venv/lib/python3.9/site-packages/celery/bin/celery.py&quot;, line 213, in main
    return celery(auto_envvar_prefix=&quot;CELERY&quot;)
  File &quot;/Users/user/Desktop/tmp/venv/lib/python3.9/site-packages/click/core.py&quot;, line 829, in __call__
    return self.main(*args, **kwargs)
  File &quot;/Users/user/Desktop/tmp/venv/lib/python3.9/site-packages/click/core.py&quot;, line 782, in main
    rv = self.invoke(ctx)
  File &quot;/Users/user/Desktop/tmp/venv/lib/python3.9/site-packages/click/core.py&quot;, line 1259, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File &quot;/Users/user/Desktop/tmp/venv/lib/python3.9/site-packages/click/core.py&quot;, line 1066, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File &quot;/Users/user/Desktop/tmp/venv/lib/python3.9/site-packages/click/core.py&quot;, line 610, in invoke
    return callback(*args, **kwargs)
  File &quot;/Users/user/Desktop/tmp/venv/lib/python3.9/site-packages/click/decorators.py&quot;, line 21, in new_func
    return f(get_current_context(), *args, **kwargs)
  File &quot;/Users/user/Desktop/tmp/venv/lib/python3.9/site-packages/celery/bin/base.py&quot;, line 132, in caller
    return f(ctx, *args, **kwargs)
  File &quot;/Users/user/Desktop/tmp/venv/lib/python3.9/site-packages/celery/bin/events.py&quot;, line 90, in events
    return _run_evcam(camera, app=app, freq=frequency, maxrate=maxrate,
  File &quot;/Users/user/Desktop/tmp/venv/lib/python3.9/site-packages/celery/bin/events.py&quot;, line 37, in _run_evcam
    return cam()
TypeError: evcam() got an unexpected keyword argument 'executable'"><pre class="notranslate"><code class="notranslate">Traceback (most recent call last):
  File "/Users/user/Desktop/tmp/venv/bin/celery", line 8, in &lt;module&gt;
    sys.exit(main())
  File "/Users/user/Desktop/tmp/venv/lib/python3.9/site-packages/celery/__main__.py", line 15, in main
    sys.exit(_main())
  File "/Users/user/Desktop/tmp/venv/lib/python3.9/site-packages/celery/bin/celery.py", line 213, in main
    return celery(auto_envvar_prefix="CELERY")
  File "/Users/user/Desktop/tmp/venv/lib/python3.9/site-packages/click/core.py", line 829, in __call__
    return self.main(*args, **kwargs)
  File "/Users/user/Desktop/tmp/venv/lib/python3.9/site-packages/click/core.py", line 782, in main
    rv = self.invoke(ctx)
  File "/Users/user/Desktop/tmp/venv/lib/python3.9/site-packages/click/core.py", line 1259, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "/Users/user/Desktop/tmp/venv/lib/python3.9/site-packages/click/core.py", line 1066, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/Users/user/Desktop/tmp/venv/lib/python3.9/site-packages/click/core.py", line 610, in invoke
    return callback(*args, **kwargs)
  File "/Users/user/Desktop/tmp/venv/lib/python3.9/site-packages/click/decorators.py", line 21, in new_func
    return f(get_current_context(), *args, **kwargs)
  File "/Users/user/Desktop/tmp/venv/lib/python3.9/site-packages/celery/bin/base.py", line 132, in caller
    return f(ctx, *args, **kwargs)
  File "/Users/user/Desktop/tmp/venv/lib/python3.9/site-packages/celery/bin/events.py", line 90, in events
    return _run_evcam(camera, app=app, freq=frequency, maxrate=maxrate,
  File "/Users/user/Desktop/tmp/venv/lib/python3.9/site-packages/celery/bin/events.py", line 37, in _run_evcam
    return cam()
TypeError: evcam() got an unexpected keyword argument 'executable'
</code></pre></div>