candidate versions found which didn't match: 0.2.17, 0.2.16, 0.2.15, ...

[SkyperTHC]

I'm not a rust person and but thought i might not be the only person who sees this:

Cargo.toml

bstr = "1"

cargo build

error: failed to select a version for the requirement `bstr = "=1.3.0"`
candidate versions found which didn't match: 0.2.17, 0.2.16, 0.2.15, ...
location searched: crates.io index

[BurntSushi]

Can you please provide a full reproduction? Also, what version of Rust are you using?

[LPGhatguy]

I hit this on a project today using Rust 1.58.1. Here is the GitHub Actions output from the MSRV build from that project: https://github.com/rojo-rbx/rojo/actions/runs/4774441218/jobs/8488120958

Upgrading to Rust 1.68.2 fixed the issue. It looks like Cargo filters out versions that require a newer version of Rust than what you're running. This UX seems bad, but nothing that needs to be fixed about bstr.

[BurntSushi]

@epage Sorry to ping you again, but this is another Cargo issue I'm not sure about. I believe I've run into this myself, where basically, a dependency has rust-version set and Cargo will just refuse to even see that crate if your version of Rust is too old. That in turn leads to really opaque errors that basically say "no version available."

I thought the main point of rust-version was to get an explicit error saying that the current version of Rust is too old? But it looks like Cargo is actually using it in version resolution somehow?

[epage]

No, its that the index entry is not understood by old versions of cargo. See rust-lang/cargo#10623

[BurntSushi]

Ah wow, didn't realize that. Thank you!