Note: It would not surprise me if this is a known issue, but I have checked for possible existing items, but while there are multiple issues about extras, I could not find any that specifically mention the combination of extras and installation from Git being an issue.
Details
```console
$ pip-compile --resolver backtracking
#
# This file is autogenerated by pip-compile with python 3.8
# To update, run:
#
# pip-compile --resolver=backtracking
#
attrs==21.4.0
# via
# automat
# service-identity
# twisted
automat==20.2.0
# via twisted
certifi==2021.10.8
# via requests
cffi==1.15.0
# via cryptography
charset-normalizer==2.0.12
# via requests
constantly==15.1.0
# via twisted
cryptography==36.0.1
# via
# pyopenssl
# scrapy
# service-identity
cssselect==1.1.0
# via
# parsel
# scrapy
h2==3.2.0
# via
# scrapy
# twisted
hpack==3.0.0
# via h2
hyperframe==5.2.0
# via h2
hyperlink==21.0.0
# via twisted
idna==3.3
# via
# hyperlink
# requests
incremental==21.3.0
# via twisted
itemadapter==0.4.0
# via
# itemloaders
# scrapy
itemloaders==1.0.4
# via scrapy
jmespath==0.10.0
# via itemloaders
lxml==4.8.0
# via
# parsel
# scrapy
parsel==1.6.0
# via
# itemloaders
# scrapy
priority==1.3.0
# via twisted
protego==0.2.1
# via scrapy
pyasn1==0.4.8
# via
# pyasn1-modules
# service-identity
pyasn1-modules==0.2.8
# via service-identity
pycparser==2.21
# via cffi
pydispatcher==2.0.5
# via scrapy
pyopenssl==22.0.0
# via scrapy
queuelib==1.6.2
# via scrapy
requests==2.27.1
# via scrapinghub
retrying==1.3.3
# via scrapinghub
scrapinghub==2.3.1
# via scrapinghub-entrypoint-scrapy
scrapinghub-entrypoint-scrapy==0.12.1
# via -r requirements.in
scrapy @ git+https://github.com/scrapy/scrapy.git@2.5.1
# via
# -r requirements.in
# scrapinghub-entrypoint-scrapy
service-identity==21.1.0
# via scrapy
six==1.16.0
# via
# automat
# parsel
# protego
# retrying
# scrapinghub
# service-identity
# w3lib
twisted[http2]==22.1.0
# via scrapy
typing-extensions==4.1.1
# via twisted
urllib3==1.26.8
# via requests
w3lib==1.22.0
# via
# itemloaders
# parsel
# scrapy
zope-interface==5.4.0
# via
# scrapy
# twisted
# The following packages are considered to be unsafe in a requirements file:
# setuptools
```
All works as expected when using regular packages:
However, if I install the very same Scrapy version from Git instead of from the Python Package Index,
twisted
is no longer frozen:Note: It would not surprise me if this is a known issue, but I have checked for possible existing items, but while there are multiple issues about extras, I could not find any that specifically mention the combination of extras and installation from Git being an issue.