error: failed to download from `https://crates.io/api/v1/crates/adler/1.0.2/download`

[xMAC94x]

Describe the bug
during cargo clippy with the toolchain 2021-07-06 crates.io often reports that it failed to download some crate.
This rise up in our CI for multiple runners, multiple crates on different times per day. At first we thought its just a network issues, but there might be more to it. did you change any of the relevant setup ?

To Reproduce
sporadic issue, it fails when cargo tries to download various crates from crates.io. see here for logs

Expected behavior
The crate adler or similar downloads corectly and cargo continues to run

Screenshots

Server (please complete the following information):

• ubuntu20.04
• cargo
• 2021-07-06

[Rustin170506]

Can this problem be reproduced in other network environments?

[MathiasKoch]

I am currently seeing similar behaviour, but it seems to be only on github actions CI.. 🤔

[insipx]

had the same issue and came across this thread https://github.community/t/failed-sending-data-to-the-peer-connection-died-tried-5-times-before-giving-up/189130

pinning nightly to that version (2021-07-05) fixed the issue for me, although I don't know what actually causes the problem. Only happened in my github CI workflow

[JohnTitor]

That seems to be a curl error, we actually bumped our curl dependency in rust-lang/rust#86874 (it's used by Cargo). But it'd be quite hard to reproduce the failure and I'm not sure either 7.76.1 or 7.77.0 would cause it. Anyway, I think this is a cargo/curl issue rather than crate.io's, cc @rust-lang/cargo for awareness.

[alexcrichton]

I tried to dig in a bit and opened an upstream issue. In the meantime rust-lang/cargo#9695 should help mitigate this issue since it will basically do more retries at a higher level (sweeping the bug under the rug)

[DaUs3103]

Please help