chore: fix MSRV build

Author: clechasseur

.github/workflows/ci.yml

@@ -98,7 +98,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        toolchain: [ 1.75.0, stable, beta, nightly ]
+        toolchain: [ 1.81.0, stable, beta, nightly ]
         os: [ ubuntu, macos, windows ]
         ignore-lock: [ false, true ]
         all-features: [ false, true ]
@@ -109,7 +109,7 @@ jobs:
           - toolchain: nightly
             experimental: true
         exclude:
-          - toolchain: 1.75.0
+          - toolchain: 1.81.0
             ignore-lock: true
     runs-on: ${{ matrix.os }}-latest
     continue-on-error: ${{ matrix.experimental }}
@@ -158,13 +158,13 @@ jobs:
       - name: Install Rust
         uses: actions-rust-lang/setup-rust-toolchain@9399c7bb15d4c7d47b27263d024f0a4978346ba4 # v1.11.0
         with:
-          toolchain: 1.75.0
+          toolchain: stable
           cache: false
 
       - name: Rust Cache
         uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
         with:
-          prefix-key: v2-rust
+          prefix-key: v3-rust
           cache-targets: false
           cache-on-failure: true
 

justfile

@@ -20,10 +20,7 @@ target_tuple_flag := if target_tuple != "" { "--target " + target_tuple } else {
 release := "false"
 release_flag := if release == "true" { "--release" } else { "" }
 
-# Note: there seems to be an issue in `cargo-tarpaulin` when using Rust 1.75.0 or later - it reports some missing line coverage.
-# I've entered an issue: https://github.com/xd009642/tarpaulin/issues/1438
-# In the meantime, let's pin the Rust version used for code coverage to 1.74.1 until we know what's happening.
-cargo_tarpaulin := tool + (if toolchain != "" { " +" + toolchain } else { " +1.74.1" }) + " tarpaulin"
+cargo_tarpaulin := tool + " tarpaulin"
 
 [private]
 default: