[openwrt/openwrt] tools/ccache: same behaviour for local and CI builds

[LEDE Commits]

ansuel pushed a commit to openwrt/openwrt.git, branch main:
https://git.openwrt.org/6f32c657db55a2e34f659d81d56aa385aaa7d69d

commit 6f32c657db55a2e34f659d81d56aa385aaa7d69d
Author: Andreas Gnau <andreas.gnau at iopsys.eu>
AuthorDate: Fri Oct 3 10:59:42 2025 +0200

    tools/ccache: same behaviour for local and CI builds
    
    If the environment variable `CI` is set, ccache will enable the CMake
    option CCACHE_DEV_MODE by default. This leads to differing behaviour
    between local and CI builds which takes quite some time to debug. 🤯
    
    Achieve consistent behaviour between local builds and CI builds by
    setting CCACHE_DEV_MODE. Set it to OFF, because CCACHE_DEV_MODE amongst
    other settings like linker choice, enables -Werror, which will lead to
    potential compilation failures when the host compiler is updated. Using
    -Werror for host utils is not desirable, because the compiler version
    used is not controlled by the OpenWrt build system and host utils should
    compile successfully on an as wide range of host OSes as possible.
    
    Reported-by: Roman Azarenko <roman.azarenko at iopsys.eu>
    Signed-off-by: Andreas Gnau <andreas.gnau at iopsys.eu>
    Link: https://github.com/openwrt/openwrt/pull/20290
    Signed-off-by: Christian Marangi <ansuelsmth at gmail.com>
---
 tools/ccache/Makefile | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tools/ccache/Makefile b/tools/ccache/Makefile
index e8ae78a5dd..86b56c123a 100644
--- a/tools/ccache/Makefile
+++ b/tools/ccache/Makefile
@@ -17,6 +17,7 @@ include $(INCLUDE_DIR)/host-build.mk
 include $(INCLUDE_DIR)/cmake.mk
 
 CMAKE_HOST_OPTIONS += \
+	-DCCACHE_DEV_MODE=OFF \
 	-DCMAKE_C_COMPILER_LAUNCHER="" \
 	-DCMAKE_CXX_COMPILER_LAUNCHER="" \
 	-DCMAKE_SKIP_RPATH=FALSE \