Include the name "pytest" somewhere in the cache directory name

[nicoddemus]

As commented by @nedbat on twitter:

I am unreasonably annoyed that pytest writes a JSON file to “.cache/v/cache/lastfailed”. Why no “pytest” in the directory? Why “cache” twice? What is “v”? Why no file extension?

People in that thread agreed with the sentiment.

[alanbato]

Hey! I'll try to take this on if you don't mind :)

[nicoddemus]

Awesome. I took a quick look at the code and keeping backward compatibility might be too tricky; if it proves itself too complicated don't mind about it, the cache is supposed to be data that might get lost eventually anyway.

[brianmaissy]

Awesome idea! +1

[nicoddemus]

Fixed by #3150

[asottile]

A bit unfortunate that I have to run around to every repository and s/\.cache/.pytest_cache/g in .gitignore due to this change.

I've at least automated this for repos I own using all-repos

I used the following command:

all-repos-sed 's/\.cache/.pytest_cache/g' .gitignore --commit-msg 'Change ignored cache dir for pytest 3.4.0'

[nicoddemus]

Nice work on all-repos, I will be definitely giving it a go sometime soon. 👍