Why was an upper bound for virtualenv version added in hatch 1.9.7?

[Oberon00]

In c18d047 (due to be released as hatch 1.9.5 / actually now in 1.9.7), the version of virtualenv was limited to virtualenv<20.26.0 and the accompanying changelog says that this was "due to a backward incompatible change". Meanwhile, I have the combination hatch 1.9.4 + virtualenv 20.26.0 running just fine. So what is this incompatibility about exactly? Is there some issue to track addressing of that incompatibility to allow upgrading virtualenv again?

[ofek]

The test suite on Windows started failing after pypa/virtualenv#2709

I'm sick but will fix within the next week.

[ofek]

I figured out the issue: pypa/virtualenv#2711