Error in Setting up the Wagtail codebase

Issue Summary

While setting up a local copy of the Wagtail git repository, running the command $ pip install -e .[testing,docs] -U generates the following error: -

ERROR: Cannot install myst_parser and wagtail because these package versions have conflicting dependencies.

The conflict is caused by:
    jinjalint 0.5 depends on attrs==17.2.0
    markdown-it-py 2.0.1 depends on attrs<22 and >=19
    jinjalint 0.5 depends on attrs==17.2.0
    markdown-it-py 2.0.0 depends on attrs<22 and >=19
    jinjalint 0.5 depends on attrs==17.2.0
    markdown-it-py 1.1.0 depends on attrs<22 and >=19
    jinjalint 0.5 depends on attrs==17.2.0
    markdown-it-py 1.0.0 depends on attrs<21 and >=19

To fix this you could try to:
1. loosen the range of package versions you've specified
2. remove package versions to allow pip attempt to solve the dependency conflict

Steps to Reproduce

1. Clone a copy of the Wagtail codebase using the following commands: -

$ git clone https://github.com/wagtail/wagtail.git
$ cd wagtail

1. With your preferred virtualenv activated, install the Wagtail package in development mode with the included testing and documentation dependencies: $ pip install -e .[testing,docs] -U

2. The error will pop up.

There is something wrong with documentation dependencies.
$ pip install -e .[testing] -U works absolutely fine.

• I have confirmed that this issue can be reproduced as described on a fresh Wagtail project: Yes

Technical details

• Python version: 3.10
• Django version: 4.0.3
• Wagtail version: 2.17a0
• Operating System: Windows/ Mac

[thibaudcolas]

#8101 ready for review! Thank you for reporting this so quickly and thoroughly @gitkaarma, makes it much much easier to figure out what the issue is.

[thibaudcolas]

@gitkaarma should be all resolved, sorry about that! Please let us know if you encounter further issues like this.