Pipenv fails to install Black 19.10b0 with pytest-black

[chrisgeru]

Pipfile:

[dev-packages]
black = "==19.10b0"
pytest = "*"
pytest-black = "*"

[pipenv]
allow_prereleases = false

works for black 19.3b0 but fails for 19.10b0 with the following error:

ERROR: ERROR: Could not find a version that matches black==19.10b0,==19.3b0
Skipped pre-versions: 18.3a0, 18.3a0, 18.3a1, 18.3a1, 18.3a2, 18.3a2, 18.3a3, 18.3a3, 18.3a4, 18.3a4, 18.4a0, 18.4a0, 18.4a1, 18.4a1, 18.4a2, 18.4a2, 18.4a3, 18.4a3, 18.4a4, 18.4a4, 18.5b0, 18.5b0, 18.5b1, 18.5b1, 18.6b0, 18.6b0, 18.6b1, 18.6b1, 18.6b2, 18.6b2, 18.6b3, 18.6b3, 18.6b4, 18.6b4, 18.9b0, 18.9b0, 19.3b0, 19.3b0, 19.10b0, 19.10b0
There are incompatible versions in the resolved dependencies.

The issue, i believe, is on this line inside setup.py:

pytest-black/setup.py

Line 29 in 7335ce2

'black==19.3b0; python_version >= "3.6"',

[paddycarey]

I think this was fixed a while back, let me know if not!

[RoelvandenBerg]

This problem resurfaces for me with the following Pipfile (and pipenv, version 2018.11.26):

[[source]]
url = "https://pypi.org/simple"
verify_ssl = true
name = "pypi"

[dev-packages]
"black" = "==19.3b0"
"pytest-black" = "==0.3.9"
"pytest" = "==5.4.*"

[requires]
python_version = "3.8"

[pipenv]
allow_prereleases = false

[thomascobb]

This is also still a problem for me with the Pipfile posted above. It seems like flake8-black has a similar issue, but has solved it by removing the minimum requirement on black: peterjc/flake8-black#22

Given that the minimum requirement on black is over a year old, would you consider doing the same for pytest-black?