Bump MSRV to 1.63

In the past I've been more cautious, but this is the version supported
by Debian Stable, and it's more than 12 months old.

A decent number of dependencies are only tested against newer rustc
versions (see e.g. the recent aho-coarasick pin due to no MSRV on that
library). I've filed bugs in some cases, but upgrading rustc versions
more aggressively should make this problem less common.

.github/workflows/deploy_docs.yml

@@ -27,7 +27,7 @@ jobs:
       - name: Install jq
         run: sudo apt-get install -y jq
 
-      - uses: dtolnay/rust-toolchain@1.60.0
+      - uses: dtolnay/rust-toolchain@1.63.0
       - run: cargo doc
 
       - name: Setup mdBook

.github/workflows/test.yml

@@ -27,7 +27,7 @@ jobs:
       uses: actions/checkout@v3
 
     - name: Install Rust toolchain
-      uses: dtolnay/rust-toolchain@1.60.0
+      uses: dtolnay/rust-toolchain@1.63.0
       with:
         targets: ${{ matrix.job.target }}
 
@@ -51,7 +51,7 @@ jobs:
     runs-on: ubuntu-20.04
     steps:
       - uses: actions/checkout@v3
-      - uses: dtolnay/rust-toolchain@1.60.0
+      - uses: dtolnay/rust-toolchain@1.63.0
       # This runs tests that rely on the MIME database being present.
       - run: cargo test -- --ignored
 
@@ -68,7 +68,7 @@ jobs:
     runs-on: ubuntu-20.04
     steps:
       - uses: actions/checkout@v3
-      - uses: dtolnay/rust-toolchain@1.60.0
+      - uses: dtolnay/rust-toolchain@1.63.0
       - name: Generate output for all sample files
         run: ./sample_files/compare_all.sh
       - name: Verify output is unchanged
@@ -79,7 +79,7 @@ jobs:
     runs-on: ubuntu-20.04
     steps:
       - uses: actions/checkout@v3
-      - uses: dtolnay/rust-toolchain@1.60.0
+      - uses: dtolnay/rust-toolchain@1.63.0
       - run: cargo package --allow-dirty
 
   fmt:
@@ -87,5 +87,5 @@ jobs:
     runs-on: ubuntu-20.04
     steps:
       - uses: actions/checkout@v3
-      - uses: dtolnay/rust-toolchain@1.60.0
+      - uses: dtolnay/rust-toolchain@1.63.0
       - run: cargo fmt --all -- --check

CHANGELOG.md

@@ -1,5 +1,9 @@
 ## 0.54 (unreleased)
 
+### Build
+
+Difftastic now requires Rust 1.63 to build.
+
 ## 0.53.1 (released 26th November 2023)
 
 ### Build

Cargo.toml

@@ -12,7 +12,7 @@ edition = "2021"
 # Goal: support at least 12 months of Rust versions, and also the Rust
 # version on Debian stable:
 # https://tracker.debian.org/pkg/rustc
-rust-version = "1.60.0"
+rust-version = "1.63.0"
 include = [
         "/build.rs",
         "/src/",

manual/src/installation.md

@@ -28,7 +28,7 @@ $ brew install difftastic
 
 Difftastic is written in Rust, so you will need Rust installed. I
 recommend [rustup](https://rustup.rs/) to install Rust. Difftastic
-requires Rust version 1.60 or later.
+requires Rust version 1.63 or later.
 
 You will also need a C++ compiler that supports C++14. If you're using
 GCC, you need at least version 8.

rust-toolchain.toml

@@ -1,4 +1,4 @@
 [toolchain]
-channel = "1.60"
+channel = "1.63"
 components = ["rustfmt"]
 profile = "minimal"

translation/zh-CN/manual-zh-CN/src/installation.md

@@ -22,7 +22,7 @@ $ brew install difftastic
 
 ### 要求
 
-Difftastic 使用 Rust 编写，所以你需安装 Rust。我推荐使用 [rustup](https://rustup.rs/) 安装 Rust。Difftastic 要求 Rust 版本不低于 1.60。
+Difftastic 使用 Rust 编写，所以你需安装 Rust。我推荐使用 [rustup](https://rustup.rs/) 安装 Rust。Difftastic 要求 Rust 版本不低于 1.63。
 
 你也需要一个支持 C++14 的 C++ 编译器。如果你正在使用 GCC，则 GCC 版本至少为 8。