Regression in version strings accepted by cargo

[weiznich]

Code

I tried this code: diesel 1.4.x

I expected to see this happen: Compilation succeeds

Instead, this happened: Compilation fails with a dependency resolution error

    Updating crates.io index
 Downloading crates ...
error: failed to download `derive-error-chain v0.10.1`
Error: failed to download `derive-error-chain v0.10.1`
Caused by:
  unable to get packages from source

Caused by:
  failed to parse manifest at `C:\Users\runneradmin\.cargo\registry\src\github.com-1ecc6299db9ec823\derive-error-chain-0.10.1\Cargo.toml`

Caused by:
  failed to parse the version requirement `0.11.x` for dependency `syn`

Steps to reproduce

git clone https://github.com/diesel-rs/diesel
cd diesel
git checkout 1.4.x
cargo +nightly test --manifest-path diesel/Cargo.toml --no-default-features --features "sqlite extras libsqlite3-sys/bundled"

This is likely related to #9508 and rust-lang/rust#85983

Version it worked on

It most recently worked on: cargo 1.53.0-beta (4369396ce 2021-04-27)

Version with regression

cargo 1.54.0-nightly (0cecbd673 2021-06-01)

@rustbot modify labels: +regression-from-stable-to-nightly -regression-untriaged

[ehuss]

Transferred to the cargo repository, as that is where cargo lives. This will be fixed by rust-lang/rust#85983.