Wait for a few minutes and retry download

[Darksonn]

Describe the problem you are trying to solve

Sometimes our CI setup on Tokio fails to download a dependency five times in a row and the build fails. Re-running it a few minutes later seems to fix it.

Describe the solution you'd like

Add an option or similar that tells cargo to sleep for a few minutes and retry again later if the download fails after retrying five times.

Notes

Cargo will currently retry a few times, which was implemented as part of #1602.

[dswij]

Although having a backoff mechanism for retry is handy such as the one implemented in curl, I'm not too convinced of having another retry after a series of retries after some time period 😕 .

In the context of CI, if backoff does not suits the purpose, perhaps there could be a separate job for downloading dependencies and have a script to retry the job after a certain time period if it fails?

[Darksonn]

Backoff sounds like a fine solution to me.