Python 3.7.0 incompatibility

[ilovezfs]

(v) bash-3.2$ pip3 install --no-binary :all: twtxt
Collecting twtxt
  Using cached https://files.pythonhosted.org/packages/3e/ea/65d5c2d8de5fd354586a193092e250c9907549026b3cda5a7be6c78e8df3/twtxt-1.2.3.tar.gz
Collecting aiohttp<3,>=2.2.5 (from twtxt)
  Using cached https://files.pythonhosted.org/packages/c0/b9/853b158f5cb5d218daaff0fb0dbc2bd7de45b2c6c5f563dff0ee530ec52a/aiohttp-2.3.10.tar.gz
  Installing build dependencies ... done
Collecting python-dateutil<3,>=2.6.1 (from twtxt)
  Using cached https://files.pythonhosted.org/packages/a0/b0/a4e3241d2dee665fea11baec21389aec6886655cd4db7647ddf96c3fad15/python-dateutil-2.7.3.tar.gz
  Installing build dependencies ... done
Collecting humanize<1,>=0.5.1 (from twtxt)
  Using cached https://files.pythonhosted.org/packages/8c/e0/e512e4ac6d091fc990bbe13f9e0378f34cf6eecd1c6c268c9e598dcf5bb9/humanize-0.5.1.tar.gz
Collecting click<7,>=6.7 (from twtxt)
  Using cached https://files.pythonhosted.org/packages/95/d9/c3336b6b5711c3ab9d1d3a80f1a3e2afeb9d8c02a7166462f6cc96570897/click-6.7.tar.gz
Collecting chardet (from aiohttp<3,>=2.2.5->twtxt)
  Using cached https://files.pythonhosted.org/packages/fc/bb/a5768c230f9ddb03acc9ef3f0d4a3cf93462473795d18e9535498c8f929d/chardet-3.0.4.tar.gz
Collecting multidict>=4.0.0 (from aiohttp<3,>=2.2.5->twtxt)
  Using cached https://files.pythonhosted.org/packages/9d/b9/3cf1b908d7af6530209a7a16d71ab2734a736c3cdf0657e3a06d0209811e/multidict-4.3.1.tar.gz
Collecting async_timeout>=1.2.0 (from aiohttp<3,>=2.2.5->twtxt)
  Using cached https://files.pythonhosted.org/packages/35/82/6c7975afd97661e6115eee5105359ee191a71ff3267fde081c7c8d05fae6/async-timeout-3.0.0.tar.gz
Collecting yarl>=1.0.0 (from aiohttp<3,>=2.2.5->twtxt)
  Using cached https://files.pythonhosted.org/packages/43/b8/057c3e5b546ff4b24263164ecda13f6962d85c9dc477fcc0bcdcb3adb658/yarl-1.2.6.tar.gz
Collecting idna-ssl>=1.0.0 (from aiohttp<3,>=2.2.5->twtxt)
  Using cached https://files.pythonhosted.org/packages/44/f4/97f7a58e814b3523a5e68bc8095c36cfa6daffb35f01b25248ec4605f53e/idna_ssl-1.0.0.tar.gz
idna-ssl requires Python '<3.7.0' but the running Python is 3.7.0
(v) bash-3.2$ 

I've hacked around in this in the Homebrew formula by patching aiohttp 2.3.10.

diff --git a/setup.py b/setup.py
index 9ca33d1..05b65f3 100644
--- a/setup.py
+++ b/setup.py
@@ -63,8 +63,7 @@ with codecs.open(os.path.join(os.path.abspath(os.path.dirname(
 
 
 install_requires = ['chardet', 'multidict>=4.0.0',
-                    'async_timeout>=1.2.0', 'yarl>=1.0.0',
-                    'idna-ssl>=1.0.0']
+                    'async_timeout>=1.2.0', 'yarl>=1.0.0']
 
 
 def read(f):

However, upstream recommends unpinning aiohttp and moving to a newer version. See aio-libs/idna-ssl#8 (comment)