Cargo: `cargo build` hangs forever on updating registry.

[christopherdumas]

I have a project (you can find it here: https://github.com/christopherdumas/guile-rs/tree/new-bindings) that causes cargo to hang indefinitely at "updating registry" while using 99.2% of my CPU. I have tried reinstalling cargo, updating Rust, etc. Nothing seems to change this behavior.
Here are the messages it prints before hanging:

warning: file found to be present in multiple build targets: /Users/christopherdumas/guile-rs/examples/shell.rs
    Updating registry `https://github.com/rust-lang/crates.io-index`

I left it running for a total of 6 hours at one point.
I'm running rustc 1.20.0-nightly (69c65d296 2017-06-28) and cargo 0.21.0-nightly (abf01e1ed 2017-06-25).

[christopherdumas]

This is not a system-wide phenomena.

[alexcrichton]

This is likely an instance of https://github.com/rust-lang/cargo/issues/4066 where the crate graph cannot be resolved and it's just taking cargo too long to inform the caller. I'd have to dig in though to confirm.

[christopherdumas]

Is there any temporary workaround that I can use for now? It's completely stopping my progress.

[alexcrichton]

Ok looks like you're hitting a combination of #4066 and https://github.com/rust-lang/cargo/issues/4127. Because of #4127 resolution fails and because of #4066 it'll take probably days to fail. What's happening here is that your lockfile indicates it wants libc 0.2.14 but you're trying to add a dependency on memchr (transitively at least) which requires libc 0.2.18.

You can fix this by running cargo update -p libc

[christopherdumas]

Thank you, its working now!

[zoltanmaric]

For me running cargo update -p libc also hangs indefinitely. It just prints

Updating registry `https://github.com/rust-lang/crates.io-index`

and then nothing else happens. Even if I add the -v flag, that's all it says.

[zoltanmaric]

Nevermind, it seems that cargo update -p libc was just taking a long time. It would be nice to log _something_ to indicate that something is happening, or at least start with a message saying that it will take while.

[johnfercher]

I'm having a problem like that. When cargo updates in my computer it works fine. When cargo updates inside a Docker container, it doesn't work.

I think you might implement a visual signal of how cargo is running. Like apt, pip or nuget, the user can see what's going on.

[jakelacey2012]

for me when running this I get an endless stream of this

DEBUG:cargo::core::resolver: checking if parking_lot v0.6.4 is already activated
DEBUG:cargo::core::resolver: checking if memoffset v0.2.1 is already activated
DEBUG:cargo::core::resolver: checking if scopeguard v0.3.3 is already activated
DEBUG:cargo::core::resolver: checking if rand v0.5.6 is already activated
DEBUG:cargo::core::resolver: checking if lazy_static v1.2.0 is already activated
DEBUG:cargo::core::resolver: checking if smallvec v0.6.8 is already activated
DEBUG:cargo::core::resolver: checking if crossbeam-utils v0.6.5 is already activated
DEBUG:cargo::core::resolver: checking if winapi v0.3.6 is already activated
DEBUG:cargo::core::resolver: checking if cfg-if v0.1.6 is already activated
DEBUG:cargo::core::resolver: checking if winapi v0.3.6 is already activated
DEBUG:cargo::core::registry: load/precise  registry https://github.com/rust-lang/crates.io-index
DEBUG:cargo::core::resolver: checking if unicode-xid v0.1.0 is already activated
DEBUG:cargo::core::registry: load/precise  registry https://github.com/rust-lang/crates.io-index
DEBUG:cargo::core::resolver: checking if unicode-xid v0.1.0 is already activated
DEBUG:cargo::core::registry: load/precise  registry https://github.com/rust-lang/crates.io-index
DEBUG:cargo::core::resolver: checking if unicode-xid v0.1.0 is already activated
DEBUG:cargo::core::registry: load/precise  registry https://github.com/rust-lang/crates.io-index
DEBUG:cargo::core::resolver: checking if unicode-xid v0.1.0 is already activated
DEBUG:cargo::core::registry: load/precise  registry https://github.com/rust-lang/crates.io-index
DEBUG:cargo::core::resolver: checking if unicode-xid v0.1.0 is already activated
DEBUG:cargo::core::registry: load/precise  registry https://github.com/rust-lang/crates.io-index
DEBUG:cargo::core::resolver: checking if unicode-xid v0.1.0 is already activated
DEBUG:cargo::core::registry: load/precise  registry https://github.com/rust-lang/crates.io-index
DEBUG:cargo::core::resolver: checking if unicode-xid v0.1.0 is already activated
DEBUG:cargo::core::registry: load/precise  registry https://github.com/rust-lang/crates.io-index
DEBUG:cargo::core::resolver: checking if unicode-xid v0.1.0 is already activated

repeated over and over when I run cargo install --verbose