Turns out it is 19 but I'm doing it wrong?

.github/workflows/linting.yaml

@@ -29,10 +29,10 @@ jobs:
       - name: Install clang-tidy
         run: |
           wget -O - https://apt.llvm.org/llvm-snapshot.gpg.key | sudo apt-key add -
-          echo "deb http://apt.llvm.org/noble/ llvm-toolchain-noble-19 main" | sudo tee /etc/apt/sources.list.d/llvm-19
-          echo "deb-src http://apt.llvm.org/noble/ llvm-toolchain-noble-19 main" | sudo tee -a /etc/apt/sources.list.d/llvm-19
+          echo "deb http://apt.llvm.org/noble/ llvm-toolchain-noble-19 main" | sudo tee /etc/apt/sources.list.d/llvm-19.list
+          echo "deb-src http://apt.llvm.org/noble/ llvm-toolchain-noble-19 main" | sudo tee -a /etc/apt/sources.list.d/llvm-19.list
           sudo apt-get update
-          sudo apt-get install -y clang-tidy-20
+          sudo apt-get install -y clang-tidy-19
 
       # Download and install cmake
       - name: Install CMake
@@ -62,7 +62,7 @@ jobs:
 
           mkdir -p ${{ github.workspace }}/.ctcache
 
-          echo CTCACHE_CLANG_TIDY='/usr/bin/clang-tidy-20' >> "$GITHUB_ENV"
+          echo CTCACHE_CLANG_TIDY='/usr/bin/clang-tidy-19' >> "$GITHUB_ENV"
           echo CTCACHE_LOCAL=1 >> "$GITHUB_ENV"
           echo CTCACHE_SAVE_OUTPUT=1 >> "$GITHUB_ENV"
           echo CTCACHE_DIR='${{github.workspace}}/.ctcache' >> "$GITHUB_ENV"

cmake/ClangTidy.cmake

@@ -1,10 +1,10 @@
 # Default not to run the clang-tidy checks, default to whatever our CI_BUILD is
 option(ENABLE_CLANG_TIDY "Enable building with clang-tidy checks.")
 if(ENABLE_CLANG_TIDY)
-  # Search for clang-tidy-15 first as this is the version installed in CI
-  find_program(CLANG_TIDY_EXECUTABLE NAMES clang-tidy-15 clang-tidy)
+  # Search for the same version of clang-tidy as is used in CI first
+  find_program(CLANG_TIDY_EXECUTABLE NAMES clang-tidy-19 clang-tidy)
   if(NOT CLANG_TIDY_EXECUTABLE)
-    message(FATAL_ERROR "clang-tidy-15 not found.")
+    message(FATAL_ERROR "clang-tidy not found.")
   endif()
 
   # Report clang-tidy executable details