From 4fabfb92371aeddf5f87f8a486f2af41caf87c03 Mon Sep 17 00:00:00 2001
From: Hanif Koh <hanifkoh@outlook.com>
Date: Wed, 9 Sep 2026 20:37:58 +0800
Subject: [PATCH] ci: build without precompiled headers when the compiler cache
 is on

Clang rebuilds the precompiled header with a fresh timestamp on every
run, so every file that includes it misses the cache: the warm run hit
178 of 927 compiles on Linux. Forward ORCA_EXTRA_BUILD_ARGS from the
macOS and Windows build scripts the way build_linux.sh already does, and
pass SLIC3R_PCH=OFF through it whenever ccache is enabled.
---
 .github/workflows/build_orca.yml | 4 ++++
 build_release_macos.sh           | 4 +++-
 build_release_vs.bat             | 4 ++--
 3 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/.github/workflows/build_orca.yml b/.github/workflows/build_orca.yml
index d9cdf7ff19..99ec5f5938 100644
--- a/.github/workflows/build_orca.yml
+++ b/.github/workflows/build_orca.yml
@@ -102,6 +102,10 @@ jobs:
           # Needed for precompiled headers and for headers a fresh checkout
           # has just written.
           echo "CCACHE_SLOPPINESS=pch_defines,time_macros,include_file_mtime,include_file_ctime" >> "$GITHUB_ENV"
+          # Clang rebuilds the precompiled header with a fresh timestamp on
+          # every run, so every file that includes it misses the cache. All
+          # three build scripts forward this to the slicer configure.
+          echo "ORCA_EXTRA_BUILD_ARGS=-DSLIC3R_PCH=OFF" >> "$GITHUB_ENV"
 
       - name: Get the version and date on Ubuntu and macOS
         if: runner.os != 'Windows'
diff --git a/build_release_macos.sh b/build_release_macos.sh
index b1de5df2e4..f8702385fa 100755
--- a/build_release_macos.sh
+++ b/build_release_macos.sh
@@ -255,6 +255,7 @@ function build_slicer() {
             mkdir -p "$PROJECT_BUILD_DIR"
             cd "$PROJECT_BUILD_DIR"
             if [ "1." != "$BUILD_ONLY". ]; then
+                read -r -a EXTRA_BUILD_ARGS <<< "${ORCA_EXTRA_BUILD_ARGS:-}"
                 cmake "${PROJECT_DIR}" \
                     -G "${SLICER_CMAKE_GENERATOR}" \
                     -DORCA_TOOLS=ON \
@@ -264,7 +265,8 @@ function build_slicer() {
                     -DCMAKE_OSX_ARCHITECTURES="${_ARCH}" \
                     -DCMAKE_OSX_DEPLOYMENT_TARGET="${OSX_DEPLOYMENT_TARGET}" \
                     -DCMAKE_IGNORE_PREFIX_PATH="${CMAKE_IGNORE_PREFIX_PATH}" \
-                    ${CMAKE_POLICY_COMPAT}
+                    ${CMAKE_POLICY_COMPAT} \
+                    "${EXTRA_BUILD_ARGS[@]}"
             fi
             cmake --build . --config "$BUILD_CONFIG" --target "$SLICER_BUILD_TARGET"
         )
diff --git a/build_release_vs.bat b/build_release_vs.bat
index 3842f1d198..aad942f7ad 100644
--- a/build_release_vs.bat
+++ b/build_release_vs.bat
@@ -164,10 +164,10 @@ cd %build_dir%
 echo on
 set CMAKE_POLICY_VERSION_MINIMUM=3.5
 if "%USE_NINJA%"=="1" (
-    cmake .. -G %CMAKE_GENERATOR% %CLANG_ARG% -DORCA_TOOLS=ON %SIG_FLAG% -DBUILD_TESTS=%BUILD_TESTS% -DCMAKE_BUILD_TYPE=%build_type%
+    cmake .. -G %CMAKE_GENERATOR% %CLANG_ARG% -DORCA_TOOLS=ON %SIG_FLAG% -DBUILD_TESTS=%BUILD_TESTS% -DCMAKE_BUILD_TYPE=%build_type% %ORCA_EXTRA_BUILD_ARGS%
     cmake --build . --config %build_type% --target all
 ) else (
-    cmake .. -G %CMAKE_GENERATOR% -A %arch% %TOOLSET_ARG% -DORCA_TOOLS=ON %SIG_FLAG% -DBUILD_TESTS=%BUILD_TESTS% -DCMAKE_BUILD_TYPE=%build_type%
+    cmake .. -G %CMAKE_GENERATOR% -A %arch% %TOOLSET_ARG% -DORCA_TOOLS=ON %SIG_FLAG% -DBUILD_TESTS=%BUILD_TESTS% -DCMAKE_BUILD_TYPE=%build_type% %ORCA_EXTRA_BUILD_ARGS%
     cmake --build . --config %build_type% --target ALL_BUILD -- -m
 )
 @echo off