Switch to workspace based lint configuration (#747)

As of the Cargo included in Rust 1.74, lints can now be configured
in `Cargo.toml` across whole crates/workspaces:
https://blog.rust-lang.org/2023/11/16/Rust-1.74.0.html
https://doc.rust-lang.org/stable/cargo/reference/manifest.html#the-lints-section
https://doc.rust-lang.org/stable/cargo/reference/workspaces.html#the-lints-table

This reduces the boilerplate, and chance that we forget to enable
lints in some targets. The only thing we need to remember is to
add the `[lints] workspace = true` to any new crates in the future.

Making this switch exposed a few places where lints weren't enabled
and issues had been missed, eg:
#746

Since this feature requires Rust 1.74, the MSRV has also been bumped.
(Though we will have had to do so soon anyway to be able to start
using `Result::inspect_err`, which is due in Rust 1.76, xref:
#723 (comment))

GUS-W-14511805.

Author: edmorley

CHANGELOG.md

@@ -11,6 +11,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Changed
 
+- Raised Minimum Supported Rust Version (MSRV) to `1.74`. ([#747](https://github.com/heroku/libcnb.rs/pull/747))
 - Improved the consistency of all user-facing libcnb.rs error message wordings. ([#722](https://github.com/heroku/libcnb.rs/pull/722))
 - The assistance error message shown when the necessary cross-compilation tools are not found now also includes the `rustup target add` step. ([#729](https://github.com/heroku/libcnb.rs/pull/729))
 - Updated the documentation for `TestRunner::build` and `TestContext::start_container` to mention when Docker resource teardown occurs. ([#743](https://github.com/heroku/libcnb.rs/pull/743))

Cargo.toml

@@ -19,10 +19,22 @@ members = [
 
 [workspace.package]
 version = "0.15.0"
-rust-version = "1.64"
+rust-version = "1.74"
 edition = "2021"
 license = "BSD-3-Clause"
 
+[workspace.lints.rust]
+unused_crate_dependencies = "warn"
+
+[workspace.lints.clippy]
+panic_in_result_fn = "warn"
+pedantic = "warn"
+unwrap_used = "warn"
+# In most cases adding error docs provides little value.
+missing_errors_doc = "allow"
+# This lint is too noisy and enforces a style that reduces readability in many cases.
+module_name_repetitions = "allow"
+
 [workspace.dependencies]
 libcnb = { version = "=0.15.0", path = "libcnb" }
 libcnb-common = { version = "=0.15.0", path = "libcnb-common" }

README.md

@@ -6,7 +6,7 @@
 [docs.rs]: https://docs.rs/libcnb/latest/libcnb/
 [Latest Version]: https://img.shields.io/crates/v/libcnb.svg
 [crates.io]: https://crates.io/crates/libcnb
-[MSRV]: https://img.shields.io/badge/MSRV-rustc_1.64+-lightgray.svg
+[MSRV]: https://img.shields.io/badge/MSRV-rustc_1.74+-lightgray.svg
 [install-rust]: https://www.rust-lang.org/tools/install
 
 `libcnb.rs` is a framework for writing [Cloud Native Buildpacks](https://buildpacks.io) in Rust.

examples/basics/Cargo.toml

@@ -5,5 +5,8 @@ edition.workspace = true
 rust-version.workspace = true
 publish = false
 
+[lints]
+workspace = true
+
 [dependencies]
 libcnb.workspace = true

examples/basics/src/main.rs

@@ -1,7 +1,3 @@
-// Enable Clippy lints that are disabled by default.
-// https://rust-lang.github.io/rust-clippy/stable/index.html
-#![warn(clippy::pedantic)]
-
 use libcnb::build::{BuildContext, BuildResult, BuildResultBuilder};
 use libcnb::detect::{DetectContext, DetectResult, DetectResultBuilder};
 use libcnb::generic::{GenericError, GenericMetadata, GenericPlatform};

examples/execd/Cargo.toml

@@ -5,6 +5,9 @@ edition.workspace = true
 rust-version.workspace = true
 publish = false
 
+[lints]
+workspace = true
+
 [dependencies]
 libcnb.workspace = true
 fastrand = "2.0.0"

examples/execd/src/bin/dice_roller.rs

@@ -1,13 +1,13 @@
-// Enable Clippy lints that are disabled by default.
-// https://rust-lang.github.io/rust-clippy/stable/index.html
-#![warn(clippy::pedantic)]
-
 use libcnb::data::exec_d::ExecDProgramOutputKey;
 use libcnb::data::exec_d_program_output_key;
 use libcnb::exec_d::write_exec_d_program_output;
 use std::collections::HashMap;
 use std::iter;
 
+// Suppress warnings due to the `unused_crate_dependencies` lint not handling integration tests well.
+#[cfg(test)]
+use libcnb_test as _;
+
 fn main() {
     write_exec_d_program_output(env_vars());
 }

examples/execd/src/main.rs

@@ -1,9 +1,3 @@
-// Enable Clippy lints that are disabled by default.
-// https://rust-lang.github.io/rust-clippy/stable/index.html
-#![warn(clippy::pedantic)]
-// This lint is too noisy and enforces a style that reduces readability in many cases.
-#![allow(clippy::module_name_repetitions)]
-
 mod layer;
 
 use crate::layer::ExecDLayer;
@@ -13,6 +7,11 @@ use libcnb::detect::{DetectContext, DetectResult, DetectResultBuilder};
 use libcnb::generic::{GenericError, GenericMetadata, GenericPlatform};
 use libcnb::{buildpack_main, Buildpack};
 
+// Suppress warnings due to the `unused_crate_dependencies` lint not handling integration tests well.
+use fastrand as _;
+#[cfg(test)]
+use libcnb_test as _;
+
 pub(crate) struct ExecDBuildpack;
 
 impl Buildpack for ExecDBuildpack {

examples/execd/tests/integration_test.rs

@@ -1,9 +1,8 @@
 //! All integration tests are skipped by default (using the `ignore` attribute)
 //! since performing builds is slow. To run them use: `cargo test -- --ignored`.
 
-// Enable Clippy lints that are disabled by default.
-// https://rust-lang.github.io/rust-clippy/stable/index.html
-#![warn(clippy::pedantic)]
+// Required due to: https://github.com/rust-lang/rust/issues/95513
+#![allow(unused_crate_dependencies)]
 
 use libcnb_test::{assert_contains, assert_empty, BuildConfig, TestRunner};
 

examples/ruby-sample/Cargo.toml

@@ -5,6 +5,9 @@ edition.workspace = true
 rust-version.workspace = true
 publish = false
 
+[lints]
+workspace = true
+
 [dependencies]
 flate2 = { version = "1.0.27", default-features = false, features = ["zlib"] }
 libcnb.workspace = true

examples/ruby-sample/src/layers/bundler.rs

@@ -30,6 +30,8 @@ impl Layer for BundlerLayer {
         }
     }
 
+    // TODO: Remove use of unwrap(): https://github.com/heroku/libcnb.rs/issues/746
+    #[allow(clippy::unwrap_used)]
     fn create(
         &self,
         context: &BuildContext<Self::Buildpack>,
@@ -84,6 +86,8 @@ impl Layer for BundlerLayer {
             })
     }
 
+    // TODO: Remove use of unwrap(): https://github.com/heroku/libcnb.rs/issues/746
+    #[allow(clippy::unwrap_used)]
     fn update(
         &self,
         context: &BuildContext<Self::Buildpack>,

examples/ruby-sample/src/main.rs

@@ -1,9 +1,3 @@
-// Enable Clippy lints that are disabled by default.
-// https://rust-lang.github.io/rust-clippy/stable/index.html
-#![warn(clippy::pedantic)]
-// This lint is too noisy and enforces a style that reduces readability in many cases.
-#![allow(clippy::module_name_repetitions)]
-
 use crate::layers::{BundlerLayer, RubyLayer};
 use crate::util::{DownloadError, UntarError};
 use libcnb::build::{BuildContext, BuildResult, BuildResultBuilder};
@@ -16,6 +10,10 @@ use libcnb::{buildpack_main, Buildpack};
 use serde::Deserialize;
 use std::process::ExitStatus;
 
+// Suppress warnings due to the `unused_crate_dependencies` lint not handling integration tests well.
+#[cfg(test)]
+use libcnb_test as _;
+
 mod layers;
 mod util;
 

examples/ruby-sample/tests/integration_test.rs

@@ -1,9 +1,8 @@
 //! All integration tests are skipped by default (using the `ignore` attribute)
 //! since performing builds is slow. To run them use: `cargo test -- --ignored`.
 
-// Enable Clippy lints that are disabled by default.
-// https://rust-lang.github.io/rust-clippy/stable/index.html
-#![warn(clippy::pedantic)]
+// Required due to: https://github.com/rust-lang/rust/issues/95513
+#![allow(unused_crate_dependencies)]
 
 use libcnb_test::{
     assert_contains, assert_not_contains, BuildConfig, ContainerConfig, PackResult, TestRunner,

libcnb-cargo/Cargo.toml

@@ -15,6 +15,9 @@ include = ["src/**/*", "LICENSE", "README.md"]
 name = "cargo-libcnb"
 path = "src/main.rs"
 
+[lints]
+workspace = true
+
 [dependencies]
 clap = { version = "4.3.24", default-features = false, features = [
   "derive",

libcnb-cargo/README.md

@@ -53,5 +53,5 @@ pack build my-image-name \
 
 [Latest Version]: https://img.shields.io/crates/v/libcnb-cargo.svg
 [crates.io]: https://crates.io/crates/libcnb-cargo
-[MSRV]: https://img.shields.io/badge/MSRV-rustc_1.64+-lightgray.svg
+[MSRV]: https://img.shields.io/badge/MSRV-rustc_1.74+-lightgray.svg
 [install-rust]: https://www.rust-lang.org/tools/install

libcnb-cargo/src/main.rs

@@ -1,10 +1,4 @@
 #![doc = include_str!("../README.md")]
-#![warn(unused_crate_dependencies)]
-#![warn(clippy::pedantic)]
-#![warn(clippy::panic_in_result_fn)]
-#![warn(clippy::unwrap_used)]
-// This lint is too noisy and enforces a style that reduces readability in many cases.
-#![allow(clippy::module_name_repetitions)]
 
 // Suppress warnings due to the `unused_crate_dependencies` lint not handling integration tests well.
 #[cfg(test)]

libcnb-cargo/tests/integration_test.rs

@@ -1,9 +1,8 @@
 //! All integration tests are skipped by default (using the `ignore` attribute)
 //! since performing builds is slow. To run them use: `cargo test -- --ignored`.
 
-// Enable Clippy lints that are disabled by default.
-// https://rust-lang.github.io/rust-clippy/stable/index.html
-#![warn(clippy::pedantic)]
+// Required due to: https://github.com/rust-lang/rust/issues/95513
+#![allow(unused_crate_dependencies)]
 
 use libcnb_common::toml_file::read_toml_file;
 use libcnb_data::buildpack::{BuildpackDescriptor, BuildpackId};
@@ -276,6 +275,8 @@ fn package_command_respects_ignore_files() {
     );
 }
 
+// Allow required due to: https://github.com/rust-lang/rust-clippy/issues/11119
+#[allow(clippy::unwrap_used)]
 fn validate_packaged_buildpack(packaged_buildpack_dir: &Path, buildpack_id: &BuildpackId) {
     assert!(packaged_buildpack_dir.join("buildpack.toml").exists());
     assert!(packaged_buildpack_dir.join("package.toml").exists());
@@ -291,6 +292,8 @@ fn validate_packaged_buildpack(packaged_buildpack_dir: &Path, buildpack_id: &Bui
     );
 }
 
+// Allow required due to: https://github.com/rust-lang/rust-clippy/issues/11119
+#[allow(clippy::unwrap_used)]
 fn validate_packaged_composite_buildpack(
     packaged_buildpack_dir: &Path,
     buildpack_id: &BuildpackId,

libcnb-common/Cargo.toml

@@ -10,6 +10,9 @@ documentation = "https://docs.rs/libcnb-common"
 readme = "README.md"
 include = ["src/**/*", "LICENSE", "README.md"]
 
+[lints]
+workspace = true
+
 [dependencies]
 serde = { version = "1.0.188", features = ["derive"] }
 thiserror = "1.0.48"

libcnb-common/README.md

@@ -8,5 +8,5 @@ This is an internal crate and should not be used by users directly. There are no
 [docs.rs]: https://docs.rs/libcnb-proc-macros/latest/libcnb_common/
 [Latest Version]: https://img.shields.io/crates/v/libcnb-common.svg
 [crates.io]: https://crates.io/crates/libcnb-common
-[MSRV]: https://img.shields.io/badge/MSRV-rustc_1.64+-lightgray.svg
+[MSRV]: https://img.shields.io/badge/MSRV-rustc_1.74+-lightgray.svg
 [install-rust]: https://www.rust-lang.org/tools/install

libcnb-common/src/lib.rs

@@ -1,9 +1,3 @@
 #![doc = include_str!("../README.md")]
-#![warn(unused_crate_dependencies)]
-#![warn(clippy::pedantic)]
-#![warn(clippy::panic_in_result_fn)]
-#![warn(clippy::unwrap_used)]
-// This lint is too noisy and enforces a style that reduces readability in many cases.
-#![allow(clippy::module_name_repetitions)]
 
 pub mod toml_file;

libcnb-data/Cargo.toml

@@ -11,6 +11,9 @@ documentation = "https://docs.rs/libcnb-data"
 readme = "README.md"
 include = ["src/**/*", "LICENSE", "README.md"]
 
+[lints]
+workspace = true
+
 [dependencies]
 fancy-regex = { version = "0.12.0", default-features = false, features = ["std"] }
 libcnb-proc-macros.workspace = true

libcnb-data/README.md

@@ -10,5 +10,5 @@ on this crate directly.
 [docs.rs]: https://docs.rs/libcnb-data/latest/libcnb_data/
 [Latest Version]: https://img.shields.io/crates/v/libcnb-data.svg
 [crates.io]: https://crates.io/crates/libcnb-data
-[MSRV]: https://img.shields.io/badge/MSRV-rustc_1.64+-lightgray.svg
+[MSRV]: https://img.shields.io/badge/MSRV-rustc_1.74+-lightgray.svg
 [install-rust]: https://www.rust-lang.org/tools/install

libcnb-data/src/lib.rs

@@ -1,10 +1,4 @@
 #![doc = include_str!("../README.md")]
-#![warn(unused_crate_dependencies)]
-#![warn(clippy::pedantic)]
-#![warn(clippy::panic_in_result_fn)]
-#![warn(clippy::unwrap_used)]
-// This lint is too noisy and enforces a style that reduces readability in many cases.
-#![allow(clippy::module_name_repetitions)]
 
 pub mod build;
 pub mod build_plan;

libcnb-package/Cargo.toml

@@ -11,6 +11,9 @@ documentation = "https://docs.rs/libcnb-package"
 readme = "README.md"
 include = ["src/**/*", "LICENSE", "README.md"]
 
+[lints]
+workspace = true
+
 [dependencies]
 cargo_metadata = "0.18.0"
 ignore = "0.4"

libcnb-package/README.md

@@ -12,5 +12,5 @@ directly.
 [docs.rs]: https://docs.rs/libcnb-package/latest/libcnb_package/
 [Latest Version]: https://img.shields.io/crates/v/libcnb-package.svg
 [crates.io]: https://crates.io/crates/libcnb-package
-[MSRV]: https://img.shields.io/badge/MSRV-rustc_1.64+-lightgray.svg
+[MSRV]: https://img.shields.io/badge/MSRV-rustc_1.74+-lightgray.svg
 [install-rust]: https://www.rust-lang.org/tools/install

libcnb-package/src/lib.rs

@@ -1,10 +1,4 @@
 #![doc = include_str!("../README.md")]
-#![warn(unused_crate_dependencies)]
-#![warn(clippy::pedantic)]
-#![warn(clippy::panic_in_result_fn)]
-#![warn(clippy::unwrap_used)]
-// This lint is too noisy and enforces a style that reduces readability in many cases.
-#![allow(clippy::module_name_repetitions)]
 
 pub mod build;
 pub mod buildpack_dependency_graph;

libcnb-proc-macros/Cargo.toml

@@ -13,6 +13,9 @@ include = ["src/**/*", "LICENSE", "README.md"]
 [lib]
 proc-macro = true
 
+[lints]
+workspace = true
+
 [dependencies]
 cargo_metadata = "0.18.0"
 fancy-regex = { version = "0.12.0", default-features = false, features = ["std"] }

libcnb-proc-macros/README.md

@@ -9,5 +9,5 @@ depending on this crate directly.
 [docs.rs]: https://docs.rs/libcnb-proc-macros/latest/libcnb_proc_macros/
 [Latest Version]: https://img.shields.io/crates/v/libcnb-proc-macros.svg
 [crates.io]: https://crates.io/crates/libcnb-proc-macros
-[MSRV]: https://img.shields.io/badge/MSRV-rustc_1.64+-lightgray.svg
+[MSRV]: https://img.shields.io/badge/MSRV-rustc_1.74+-lightgray.svg
 [install-rust]: https://www.rust-lang.org/tools/install

libcnb-proc-macros/src/lib.rs

@@ -1,8 +1,4 @@
 #![doc = include_str!("../README.md")]
-#![warn(unused_crate_dependencies)]
-#![warn(clippy::pedantic)]
-#![warn(clippy::panic_in_result_fn)]
-#![warn(clippy::unwrap_used)]
 
 use proc_macro::TokenStream;
 use quote::quote;

libcnb-test/Cargo.toml

@@ -11,6 +11,9 @@ documentation = "https://docs.rs/libcnb-test"
 readme = "README.md"
 include = ["src/**/*", "LICENSE", "README.md"]
 
+[lints]
+workspace = true
+
 [dependencies]
 fastrand = "2.0.0"
 fs_extra = "1.3.0"

libcnb-test/README.md

@@ -226,5 +226,5 @@ fn additional_buildpacks() {
 [docs.rs]: https://docs.rs/libcnb-test/latest/libcnb_test/
 [Latest Version]: https://img.shields.io/crates/v/libcnb-test.svg
 [crates.io]: https://crates.io/crates/libcnb-test
-[MSRV]: https://img.shields.io/badge/MSRV-rustc_1.64+-lightgray.svg
+[MSRV]: https://img.shields.io/badge/MSRV-rustc_1.74+-lightgray.svg
 [install-rust]: https://www.rust-lang.org/tools/install

libcnb-test/src/lib.rs

@@ -1,11 +1,4 @@
 #![doc = include_str!("../README.md")]
-// Enable lints that are disabled by default.
-#![warn(unused_crate_dependencies)]
-#![warn(clippy::pedantic)]
-#![warn(clippy::panic_in_result_fn)]
-#![warn(clippy::unwrap_used)]
-// This lint is too noisy and enforces a style that reduces readability in many cases.
-#![allow(clippy::module_name_repetitions)]
 
 mod app;
 mod build;

libcnb-test/tests/integration_test.rs

@@ -5,9 +5,8 @@
 //! to test dynamic values, in which case the only option is to use `panic::catch_unwind`
 //! since `should_panic` doesn't support globs/regular expressions/compile time macros.
 
-// Enable Clippy lints that are disabled by default.
-// https://rust-lang.github.io/rust-clippy/stable/index.html
-#![warn(clippy::pedantic)]
+// Required due to: https://github.com/rust-lang/rust/issues/95513
+#![allow(unused_crate_dependencies)]
 
 use indoc::{formatdoc, indoc};
 use libcnb_data::buildpack_id;

libcnb/Cargo.toml

@@ -11,6 +11,9 @@ documentation = "https://docs.rs/libcnb"
 readme = "README.md"
 include = ["src/**/*", "LICENSE", "README.md"]
 
+[lints]
+workspace = true
+
 [dependencies]
 anyhow = { version = "1.0.75", optional = true }
 cyclonedx-bom = { version = "0.4.0", optional = true }