Add retry/backoff to file removing on Windows

[wolfv]

When overwriting a file on prefix updates it might try to overwrite a file that is still in use. The workaround is to stop all usages of the prefix before an update.

Where is this important

A common use-case is in a pixi project that is activated/used in an IDE. These IDE's might be using the Python Interpreter for the language server.

The error you'll get on a package update will then look like this:

❯ pixi add python>3.11
  ⠁ validate cache       [00:00:00] [━━━━━━━━━━━━━━━━━╾──] python (+1)
  ⠁ download & extract   [00:00:00] [────────────────────]      0 B @ 0 B/s    pydantic-core (+1)
  ⠁ installing packages  [00:00:00] [━╾──────────────────]     2/30 python (+14)
  × failed to unlink python-3.10.15-hfaddaf0_2_cpython.conda
  ╰─▶ failed to delete file: DLLs/_ctypes.pyd

Which is hard to read and UX unfriendly. A way to avoid this error entirely would be an amazing improvement for the UX.

Solution

This has been done before in mamba, by renaming it to a xxx.conda_trash. Then another run could look for all the trash files and actually remove them.

Initial issue:
Sometimes, removing a file that was (just) in use fails on Windows. I think it's good practice to add a retry after a few ms or more (we also hit something like that in pixi and fixed it with a sleep: prefix-dev/pixi@0ee497f

[adament]

If I were to take a stab at this, would you prefer to have a design discussion here first or that I just make an attempt at it and then we can have a discussion on the preferred solution in the pull request?

[baszalmstra]

Awesome! The issue already contains a possible solution, but if you have other ideas feel free to discuss it here or implement it right away.