[OE-core] [PATCH] cmake: fix compiling some C++ projects with Yocto SDK and GCC

[Urs Fässler]

Setting CMAKE_SYSROOT in the toolchain file allows CMake to correctly
remove user-provided system include directories pointing to
<sysroot>/usr/include. The mentioned projects failed with "stdlib.h:
No such file or directory #include_next <stdlib.h>".

Signed-off-by: Urs Fässler <urs.fassler at bbv.ch>
Signed-off-by: Raphael Freudiger <raphael.freudiger at siemens.com>
---
 meta/recipes-devtools/cmake/cmake/OEToolchainConfig.cmake | 1 +
 1 file changed, 1 insertion(+)

diff --git a/meta/recipes-devtools/cmake/cmake/OEToolchainConfig.cmake b/meta/recipes-devtools/cmake/cmake/OEToolchainConfig.cmake
index d52c29e5a1..8a0fb4cb12 100644
--- a/meta/recipes-devtools/cmake/cmake/OEToolchainConfig.cmake
+++ b/meta/recipes-devtools/cmake/cmake/OEToolchainConfig.cmake
@@ -3,6 +3,7 @@ set( CMAKE_C_FLAGS $ENV{CFLAGS} CACHE STRING "" FORCE )
 set( CMAKE_CXX_FLAGS $ENV{CXXFLAGS}  CACHE STRING "" FORCE )
 set( CMAKE_ASM_FLAGS ${CMAKE_C_FLAGS} CACHE STRING "" FORCE )
 set( CMAKE_LDFLAGS_FLAGS ${CMAKE_CXX_FLAGS} CACHE STRING "" FORCE )
+set( CMAKE_SYSROOT $ENV{OECORE_TARGET_SYSROOT} )
 
 set( CMAKE_FIND_ROOT_PATH $ENV{OECORE_TARGET_SYSROOT} $ENV{OECORE_NATIVE_SYSROOT} )
 set( CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER )
-- 
2.18.0