cargo install cargo-tarpaulin fails: native-tls 0.2.17 compile error (Protocol::Tlsv13 non-exhaustive)

## Summary `cargo install cargo-tarpaulin` (any recent version) fails to compile because it resolves `native-tls` to `v0.2.17`, which has a regression: the `Protocol::Tlsv13` variant is defined in the enum but not handled in the openssl backend. ## Error ``` error[E0004]: non-exhaustive patterns: `Some(Protocol::Tlsv13)` not covered --> native-tls-0.2.17/src/imp/openssl.rs:61:22 error[E0004]: non-exhaustive patterns: `Some(Protocol::Tlsv13)` not covered --> native-tls-0.2.17/src/imp/openssl.rs:75:22 error: failed to compile `cargo-tarpaulin v0.35.1` ``` ## Reproduction ``` cargo install cargo-tarpaulin ``` Fails because cargo resolves `native-tls` to `0.2.17`. Affects all recent tarpaulin versions that depend on `native-tls ^0.2`. ## Environment - `cargo-tarpaulin`: 0.35.1 - `native-tls`: 0.2.17 (resolved by cargo) - `rustc`: 1.93.0-nightly (c23ed3ef2 2025-11-23) - OS: Linux (x86_64) ## Workaround Use `--locked` to pin transitive deps to tarpaulin's published Cargo.lock (which resolves to `native-tls v0.2.14`): ``` cargo install cargo-tarpaulin --locked ``` ## Root cause The bug is in `native-tls 0.2.17` itself. Filed upstream: https://github.com/rust-native-tls/rust-native-tls/issues/370 A fix on tarpaulin's side would be to either: - Bump the minimum `native-tls` version once a fix is released, or - Document `--locked` as the recommended install method