[CI] Try to debug ccache not ccaching anything on Windows + MSVC

Author: pitrou

.github/workflows/cpp.yml

@@ -27,6 +27,7 @@ on:
     paths:
       - '.dockerignore'
       - '.github/workflows/cpp.yml'
+      - '.github/workflows/cpp_windows.yml'
       - 'ci/conda_env_*'
       - 'ci/docker/**'
       - 'ci/scripts/ccache_setup.sh'
@@ -44,6 +45,7 @@ on:
     paths:
       - '.dockerignore'
       - '.github/workflows/cpp.yml'
+      - '.github/workflows/cpp_windows.yml'
       - 'ci/conda_env_*'
       - 'ci/docker/**'
       - 'ci/scripts/ccache_setup.sh'

.github/workflows/cpp_windows.yml

@@ -72,6 +72,8 @@ jobs:
       CMAKE_CXX_STANDARD: "20"
       CMAKE_GENERATOR: Ninja
       CMAKE_INSTALL_PREFIX: /usr
+      # ccache does not support PDB files (https://github.com/ccache/ccache/issues/1040)
+      CMAKE_MSVC_DEBUG_INFORMATION_FORMAT: Embedded
       CMAKE_UNITY_BUILD: ON
     steps:
       - name: Disable Crash Dialogs

.github/workflows/ruby.yml

@@ -386,6 +386,9 @@ jobs:
       CMAKE_CXX_STANDARD: "20"
       CMAKE_GENERATOR: Ninja
       CMAKE_INSTALL_PREFIX: "${{ github.workspace }}/dist"
+      # ccache does not support PDB files (https://github.com/ccache/ccache/issues/1040)
+      CMAKE_MSVC_DEBUG_INFORMATION_FORMAT: Embedded
+      CMAKE_UNITY_BUILD: ON
       VCPKG_BINARY_SOURCES: 'clear;nugettimeout,600;nuget,GitHub,readwrite'
       VCPKG_DEFAULT_TRIPLET: x64-windows
     permissions:

ci/scripts/cpp_build.sh

@@ -269,6 +269,7 @@ else
     -DCMAKE_CXX_STANDARD="${CMAKE_CXX_STANDARD:-20}" \
     -DCMAKE_INSTALL_LIBDIR=${CMAKE_INSTALL_LIBDIR:-lib} \
     -DCMAKE_INSTALL_PREFIX=${CMAKE_INSTALL_PREFIX:-${ARROW_HOME}} \
+    -DCMAKE_MSVC_DEBUG_INFORMATION_FORMAT=${CMAKE_MSVC_DEBUG_INFORMATION_FORMAT:-} \
     -DCMAKE_UNITY_BUILD=${CMAKE_UNITY_BUILD:-OFF} \
     -DCUDAToolkit_ROOT=${CUDAToolkit_ROOT:-} \
     -Dgflags_SOURCE=${gflags_SOURCE:-} \