Yanked subdependency - Error [E0433]: failed to resolve: could not find `__rt` in `quote`

Question

I'm learning Rust from "Practical Rust Projects" by Shing Lyu. I'm now trying to build a game following the steps in Chapter 4. I'm working on Ubuntu 18.04 LTS.

After installing Rust and the Amethyst command line, I created a new project via amethyst new cat_volleyball. The next step is to run the engine using cargo run --features=vulkan . When I do so, I get the error prompt below. Do you have suggestions on how to fix this?

error[E0433]: failed to resolve: could not find `__rt` in `quote`
   --> /home/alberto/.cargo/registry/src/github.com-1ecc6299db9ec823/err-derive-0.1.6/src/lib.rs:145:63
    |
145 | fn display_body(s: &synstructure::Structure) -> Option<quote::__rt::TokenStream> {
    |                                                               ^^^^ could not find `__rt` in `quote`

error: aborting due to previous error

For more information about this error, try `rustc --explain E0433`.
error: could not compile `err-derive`.
warning: build failed, waiting for other jobs to finish...

Answer 1

TL;DR Edit the Cargo.lock manually, please check the title below for the proper steps : How to force cargo to use yanked version of sub-dependency

---

Why this happens ?

Because err-derive-0.1.6 is using quote-1.0.2 as a dependency and quote is declared like below:

[dependencies.quote]
version = "1.0.2"

It means Cargo will use the latest patch update, so if quote-1.0.3 is out then cargo will use 1.0.3 instead 1.0.2. Please check caret-requirement. The problem in here is quote-1.0.3 breaks the backward compatibility, the part that used by err-derive-0.1.6 is no longer exists in quote-1.0.3.

How to force cargo to use specific version of sub-dependency

You can fix this issue by forcing the sub-dependency to use compatible version for your dependency. This command will do it :

> cargo update -p quote --precise 1.0.2 

How to force cargo to use yanked version of sub-dependency

Looks like quote-1.0.2 was yanked from crates.io, so command up above will not work because cargo will not be able to find the yanked version on crates.io . Since cargo update modifies the cargo.lock we can do it manually. To start clean :

1. Remove Cargo.lock
2. Run cargo update ( this will generate the latest version of Cargo.lock )
3. Edit Cargo.lock :

Find the incompatible version of package in cargo.lock which is quote-1.0.3, It should look like this:

[[package]]
name = "quote"
version = "1.0.3"
source = "registry+https://github.com/rust-lang/crates.io-index"
dependencies = [
 "proc-macro2 1.0.9 (registry+https://github.com/rust-lang/crates.io-index)",
]

then simply change version to the compatible version in our case it is "1.0.2"

[[package]]
name = "quote"
version = "1.0.2"

After doing that do not run cargo update again, it will overwrite your changes and you'll not able to compile your project. Please remember this is a workaround for being able to continue the development, there is a reason to yank crates, do not use it in production it is best to wait dependent crates to update itself.

---

Note : In some cases you may get an error after editing cargo.lock:

error: Found argument 'Cargo.lock' which wasn't expected, or isn't valid in this context

@albus_c fixed this by doing :

A note for posterity: I fixed the issue removing rustc (sudo apt remove rustc) and reinstalled as recommended on the Rust website, curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh After that everything worked fine.