Do not cancel downloads behind proxy just because it is slow

[lostiniceland]

PS C:\Dev\git\project> cargo build
 Downloading serde_json v1.0.11
warning: spurious network error (2 tries remaining): [28] Timeout was reached (Operation too slow. Less than 10 bytes/sec transferred the last 1705032704 seconds)
warning: spurious network error (1 tries remaining): [28] Timeout was reached (Operation too slow. Less than 10 bytes/sec transferred the last 1705032704 seconds)
error: unable to get packages from source

Our company proxy is also scanning the downloaded artefacts. While doing so, it still sends some data (5 bytes/sec), probably in order to keep the connection alive.
Cargo thinks this is to slow and stops with an error.

Can we have an option to ignore this check?

[alexcrichton]

You should be able to add global .cargo/config configuration like:

[http]
timeout = 1000000

would that work for your use case?

[lostiniceland]

Unfortunately not. I am already using a very long timeout.

The error message also does not appear after a certain amount of time(out). It is immediately appearing (I assume as soon as the connection is established). I've tried many things, including a local mirror of the crates.io-index. The index seems to be ok, since it is trying to download the first crate.

As said, and as others have reported, I guess it wouldnt be a problem if our proxy wouldn't send any data. But it does, which must trigger some exception in the cargo chain.

[alexcrichton]

Hm this may either be a bug in curl, the proxy, or a timeout in curl that we accidentally aren't configuring? I'm not entirely sure unfortunately :(

If you're using a super long timeout already though and it's failing quickly, then that probably means it's a bug in how we're telling curl about timeouts (maybe we're missing one?)

[lostiniceland]

Curl provides these two options

• https://curl.haxx.se/libcurl/c/curl_easy_setopt.html#CURLOPTLOWSPEEDLIMIT
• https://curl.haxx.se/libcurl/c/curl_easy_setopt.html#CURLOPTLOWSPEEDTIME

An option to override those would probably be enough. Or Cargo sets higher values if a proxy is configured.

[alexcrichton]

It looks like Cargo doesn't currently have the ability to overrides its configuration of low_speed_limit and that may do the trick! (Providing the ability to override that)

[lostiniceland]

Thanks for providing the location. This is exactly our problem since the proxy only sends 5 bytes/sec.

I can try to work on a PR.
Can I just replace my local cargo binary with an updated one for testing? Or is there a better way?

[alexcrichton]

Ah yeah a cargo build in this repository should produce another cargo binary and you should be able to use that one in-place instead of the already installed version

[lostiniceland]

Here´s how to reproduce the issue (adjust tc to your network adapter).

sudo tc qdisc add dev eth0 handle 1: root htb default 11 && sudo tc class add dev eth0 parent 1: classid 1:1 htb rate 5bps && sudo tc class add dev eth0 parent 1:1 classid 1:11 htb rate 5bps

to clear tc call
sudo tc qdisc del dev eth0 root

How to reproduce (you have to limit bandwith after the index is updated and cargo starts downloading crates...otherwise a simple timeout will occur)

• clear cargo download cache

• start a cargo build

• wait for the crate download to start

• execute the tc command to limit bandwith under 10bps

• note that the first connection fails with the low-speed...the next retry will timeout because the connection cannot be established quick enough

• clear tc

Result (without stupid company proxy)

$ cargo build
Downloading log v0.4.4
Downloading termcolor v1.0.2
Downloading rustfix v0.4.2
Downloading tempfile v3.0.3
Downloading lazycell v1.0.0
Downloading hex v0.3.2
Downloading rustc-workspace-hack v1.0.0
warning: spurious network error (2 tries remaining): [28] Timeout was reached (Operation too slow. Less than 10 bytes/sec transferred the last 5 seconds)
warning: spurious network error (1 tries remaining): [7] Couldn't connect to server (Failed to connect to crates.io port 443: Connection timed out)
Fetch [ ] 0.00%