fix(ci): improve compilation speed

Author: andogq

.cargo/mutants.toml

@@ -1,3 +1,5 @@
+profile = "mutants"
+
 exclude_globs = [
     "src/passes/codegen.rs", # Until LLVM snapshot tests are implemented.
     "src/ty/solver.rs", # Until solver is hardened and tested.

.github/actions/setup/action.yaml

@@ -8,10 +8,21 @@ inputs:
   llvm-version:
     description: Version of LLVM to install.
     required: true
+  tmpfs-path:
+    description: Path to tmpfs
+    default: /ram
+    required: false
 
 runs:
   using: composite
   steps:
+    - name: Setup tmpfs
+      shell: bash
+      run: |
+        sudo mkdir '${{ inputs.tmpfs-path }}'
+        sudo mount -t tmpfs '${{ inputs.tmpfs-path }}' '${{ inputs.tmpfs-path }}'
+        sudo chmod 1777 '${{ inputs.tmpfs-path }}'
+
     - name: Install LLVM Dependencies
       shell: bash
       run: |
@@ -31,3 +42,5 @@ runs:
         rustup toolchain install stable --profile minimal --no-self-update
 
     - uses: Swatinem/rust-cache@v2
+
+# spell-checker:ignore libtinfo,Swatinem,tmpfs

.github/workflows/ci.yaml

@@ -8,8 +8,10 @@ on:
 
 env:
   CARGO_TERM_COLOR: "always"
+  CARGO_INCREMENTAL: 0
   LLVM_PATH: "${{ github.workspace }}/llvm"
   LLVM_VERSION: "18.1"
+  TMPDIR: "/ram"
 
 jobs:
   test:
@@ -22,6 +24,7 @@ jobs:
         with:
           llvm-version: ${{ env.LLVM_VERSION }}
           llvm-path: ${{ env.LLVM_PATH }}
+          tmpfs-path: /ram
 
       - name: Install cargo-llvm-cov and nextest
         uses: taiki-e/install-action@v2
@@ -60,6 +63,7 @@ jobs:
         with:
           llvm-version: ${{ env.LLVM_VERSION }}
           llvm-path: ${{ env.LLVM_PATH }}
+          tmpfs-path: /ram
 
       - name: Run clippy
         run: |
@@ -87,6 +91,7 @@ jobs:
         with:
           llvm-version: ${{ env.LLVM_VERSION }}
           llvm-path: ${{ env.LLVM_PATH }}
+          tmpfs-path: /ram
 
       - name: Install cargo-mutants and nextest
         uses: taiki-e/install-action@v2
@@ -101,4 +106,4 @@ jobs:
           name: mutants-out
           path: mutants.out
 
-# spell-checker:ignore libtinfo,Swatinem
+# spell-checker:ignore tmpfs

Cargo.toml

@@ -12,3 +12,7 @@ thiserror = "2.0.17"
 insta = "1.46.0"
 mockall = "0.14.0"
 rstest = "0.26.1"
+
+[profile.mutants]
+inherits = "test"
+debug = "none"