Move to Rust 2024

.github/workflows/rust.yml

@@ -13,7 +13,7 @@ env:
   CARGO_TERM_COLOR: always
   RUSTFLAGS: -Dwarnings
   RUST_BACKTRACE: full
-  rust_min: 1.82.0 # <- Update this when bumping up MSRV
+  rust_min: 1.85.0 # <- Update this when bumping up MSRV
 
 jobs:
   static_checks:
@@ -122,14 +122,12 @@ jobs:
         toolchain: ${{ env.rust_min }}
     - name: Print Rust version
       run: rustc --version
-    - name: Use MSRV Cargo.lock
-      run: mv Cargo.lock.msrv Cargo.lock
     - name: MSRV cargo check with features
-      run: cargo check --all-targets --all-features --locked
+      run: cargo check --all-targets --all-features
     - name: MSRV cargo check without features
-      run: cargo check --all-targets --locked -p scylla
+      run: cargo check --all-targets -p scylla
     - name: MSRV cargo check scylla-cql
-      run: cargo check --all-targets --locked -p scylla-cql
+      run: cargo check --all-targets -p scylla-cql
 
   # Tests that docstrings generate docs without warnings
   cargo_docs:

CONTRIBUTING.md

@@ -78,38 +78,6 @@ simply add the call at the beginning of the test.
 Before sending a pull request, it is a good idea to run `make ci` locally (or `make dockerized-ci` if on macOS).
 It will perform a format check, `cargo check`, linter check (clippy), build and `cargo test`.
 
-### min_rust workflow and Cargo.lock.msrv
-
-There is min_rust job defined in rust.yml workflow that checks if the driver compiles with our current MSRV.
-Bumping MSRV is generally not considered a breaking change, so our dependencies are free to do it,
-and do it regularly. This resulted in failures in this job.
-We could pin versions of problematic crates in `Cargo.toml`, but it would affect version selection
-for client applications. It would also force people that use non-ancient versions of Rust to use older
-versions of dependencies, which is not desirable.
-
-We opted for a different approach. There is `Cargo.lock.msrv` file in repository, which is used only by min_rust job - 
-it is renamed to `Cargo.lock` before building the driver with `--locked` flag.
-
-This solution is good for us (because we don't have to fix breakage so often) and for users of the driver on modern versions
-of Rust - for them the driver will just work.
-Users on old versions of Rust will potentially have to pin indirect dependencies to specific versions - but that shouldn't be
-that much of a problem, it's just few `cargo update` commands.
-
-If your PR added / removed / updated a dependency, you will need to also update `Cargo.lock.msrv` file.
-There are a few scenarios:
- - If you just bumped version of one of crates in the workspace: rename `Cargo.lock.msrv` to `Cargo.lock`,
-    run `cargo check --all-targets --all-features --offline`, rename the file back.
- - If you added / removed / updated dependency in one of `Cargo.toml` files it should be enough to
-    rename `Cargo.lock.msrv` to `Cargo.lock`, run `cargo check --all-targets --all-features`
-    and rename the file back.
- - If previous methods didn't work or you want to recreate the file (which we should do once in a while):
-      1. Switch to MSRV version (e.g. `rustup install <current-msrv> && rustup default <current-msrv>`). Check `README.md` file for current MSRV.
-      2. Remove your `Cargo.lock`
-      3. Run `cargo check --all-targets --all-features`
-      4. If you got an error about one of dependencies not working with this version of Rust, update it's version in `Cargo.lock`,
-         using command like `cargo update -p toml_datetime --precise 0.6.3` and go back to step 3.
-      5. Rename `Cargo.lock` to `Cargo.lock.msrv`.
-
 ### Semver checking
 
 Our CI runs cargo semver-checks and labels PRs that introduce breaking changes.