Yank rand 0.7.1 due to failure to compile with unresolved rand_core::OsRng import

[joshsleeper]

Common issues

Problem: rand 0.7.1 is failing to compile with the following error:

$ cargo check
    Checking rand v0.7.1
error[E0432]: unresolved import `rand_core::OsRng`
   --> /home/jsleeper/.cargo/registry/src/github.aaakk.us.kg-1ecc6299db9ec823/rand-0.7.1/src/rngs/mod.rs:119:37
    |
119 | #[cfg(feature="getrandom")] pub use rand_core::OsRng;
    |                                     ^^^^^^^^^^^^^^^^ no `OsRng` in the root

error: aborting due to previous error

For more information about this error, try `rustc --explain E0432`.
error: Could not compile `rand`.

To learn more, run the command again with --verbose.

Quick solutions:

• run cargo update
  OR
• run cargo update --package rand_core to force just rand_core to update

Details: A quick look and test makes me think (if I'm reading Cargo.toml correctly) this might be due to rand 0.7.1 requiring changes from rand_core 0.5.1, but only technically depending on rand_core 0.5?

rand_core dep requirement in Cargo.toml: https://github.com/rust-random/rand/blob/master/Cargo.toml#L57

rand_core 0.5.1 changelog: https://github.com/rust-random/rand/blob/master/rand_core/CHANGELOG.md#051---2019-08-28

[benesch]

Also just ran into it, and I agree with @joshsleeper's assessment. Dependabot compatibility for the release is only 33%: https://dependabot.com/compatibility-score/?dependency-name=rand&package-manager=cargo&previous-version=0.7.0&new-version=0.7.1.

[dhardy]

Aha. Thanks for the report; sounds like we should fix this asap!

[dhardy]

I've pushed the version bump into #888. Since this only adds tests, it should be fine adding this into the release.

[dhardy]

Note: rand 0.7.1 has been yanked because of this bug which presents a significant trip hazard when updating rand without also updating rand_core.