Taken from upstream: https://github.com/pdoc3/pdoc/commit/4aa70de2221a34a3003a7e5f52a9b91965f0e359.patch.

From 4aa70de2221a34a3003a7e5f52a9b91965f0e359 Mon Sep 17 00:00:00 2001
From: Spencer Baugh <sbaugh@catern.com>
Date: Thu, 23 Sep 2021 09:00:25 -0400
Subject: [PATCH] TST: use explicit ClassWithNew instead of typing.Generic

typing.Generic doesn't have a __new__ method in 3.9.

Fixes https://github.com/pdoc3/pdoc/issues/355
---
 pdoc/test/__init__.py | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/pdoc/test/__init__.py b/pdoc/test/__init__.py
index e8c3d94..8b67ab7 100644
--- a/pdoc/test/__init__.py
+++ b/pdoc/test/__init__.py
@@ -1043,16 +1043,20 @@ class C2:
 
         self.assertEqual(pdoc.Class('C2', mod, C2).params(), ['a', 'b', 'c=None', '*', 'd=1', 'e'])
 
-        class G(typing.Generic[T]):
+        class ClassWithNew:
+            def __new__(self, arg):
+                pass
+
+        class G(ClassWithNew):
             def __init__(self, a, b, c=100):
                 pass
 
         self.assertEqual(pdoc.Class('G', mod, G).params(), ['a', 'b', 'c=100'])
 
-        class G2(typing.Generic[T]):
+        class G2(ClassWithNew):
             pass
 
-        self.assertEqual(pdoc.Class('G2', mod, G2).params(), ['*args', '**kwds'])
+        self.assertEqual(pdoc.Class('G2', mod, G2).params(), ['arg'])
 
     def test_url(self):
         mod = pdoc.Module(EXAMPLE_MODULE)
80516fa7cc'>commit</a><a href='/guix/diff/etc/time-travel-manifest.scm?id=fdf09bcd311b093bd10f0fb35fa4db80516fa7cc'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/etc/time-travel-manifest.scm'>
<input type='hidden' name='id' value='fdf09bcd311b093bd10f0fb35fa4db80516fa7cc'/><select name='qt'>
<option value='grep'>log msg</option>
<option value='author'>author</option>
<option value='committer'>committer</option>
<option value='range'>range</option>
</select>
<input class='txt' type='search' size='10' name='q' value=''/>
<input type='submit' value='search'/>
</form>
</td></tr></table>
<div class='path'>path: <a href='/guix/log/?id=fdf09bcd311b093bd10f0fb35fa4db80516fa7cc'>root</a>/<a href='/guix/log/etc?id=fdf09bcd311b093bd10f0fb35fa4db80516fa7cc'>etc</a>/<a href='/guix/log/etc/time-travel-manifest.scm?id=fdf09bcd311b093bd10f0fb35fa4db80516fa7cc'>time-travel-manifest.scm</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/etc/time-travel-manifest.scm?id=fdf09bcd311b093bd10f0fb35fa4db80516fa7cc&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2022-08-17 15:42:56 +0200'>2022-08-17</span></td><td><a href='/guix/commit/etc/time-travel-manifest.scm?id=845c841e21379e64a4215ee6d3d60da343e7fb93'>time-travel-manifest: Use a separate cache per system.</a><span class='msg-avail'>...<span class='msg-tooltip'>* etc/time-travel-manifest.scm (&lt;guix-instance-compiler&gt;): Use a separate
cache per system so that parallel system evaluations do no step on each
other's toes.
</span></span></td><td>Mathieu Othacehe</td></tr>
<tr><td><span title='2022-07-10 23:57:14 +0200'>2022-07-10</span></td><td><a href='/guix/commit/etc/time-travel-manifest.scm?id=5d0437ea8ce0147b47b9df866fa2413b48f71a1a'>time-travel-manifest: Use a separate Git checkout cache.</a><span class='msg-avail'>...<span class='msg-tooltip'>* etc/time-travel-manifest.scm (guix-instance-compiler): Parameterize
%REPOSITORY-CACHE-DIRECTORY.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2022-07-08 23:58:11 +0200'>2022-07-08</span></td><td><a href='/guix/commit/etc/time-travel-manifest.scm?id=e80f0cda96181d90604c44f69094f2499036b3f6'>etc: Add 'time-travel-manifest.scm'.</a><span class='msg-avail'>...<span class='msg-tooltip'>This manifest makes it easy to test travels from the current revision
back to the revision of a past Guix release.

Suggested by zimoun &lt;zimon.toutoune@gmail.com&gt;.

* etc/time-travel-manifest.scm: New file.
* Makefile.am (EXTRA_DIST): Add it.
</span></span></td><td>Ludovic Courtès</td></tr>