pytest should not have any external python requirements

[zefr0x]

What's the problem?

At this point of time pytest use at most 7 external python requirements to work:

iniconfig
packaging
pluggy>=0.12,<2.0
colorama;sys_platform=="win32"
exceptiongroup>=1.0.0rc8;python_version<"3.11"
importlib-metadata>=0.12;python_version<"3.8"
tomli>=1.0.0;python_version<"3.11"

There is a chance that we will face a conflict in some projects, since one of those requirements might be used in them with other version ranges. In most cases we can't run pytest without the project we want to test satisfying it's own requirements.

With a quick search, this has been historically problematic: #3381

Describe the solution you'd like

pytest is a tool that will be used in a lot of different projects, it is intended as a utility and should has nothing to do with the project itself. I think it should be portable. It might be possible to just not use unnecessary requirements (they were not added for some trivial reason so this is not a solution). For other important ones we can just include them as a git submodule and ship them embedded with pytest it self.

I think that the git submodule solution is the best one.

Anyway, this is what I think from my point of view, I might be wrong.

[RonnyPfannschmidt]

most of those are backports for old pythons and managed in a responsible manner
then comes packaging, which is just leaving standard implementations where

colorama is there bacause for about a decade colors on windows where a mess vendoring it would just break even more things

then there is iniconfig and pluggy, which are intentionally externalized

so nope

additionally git submodules are a very error prone an huer hostile way to manage vendored packages 👎