Release build with debug symbols (RelWithDebInfo)

[aristotelos]

Is there an option to build your dependencies as a release build with debug symbols (CMake RelWithDebInfo build type)? At the moment, debug symbols are not present for dependencies in a Linux build when building with CMAKE_BUILD_TYPE RelWithDebInfo and using the triplet x64-linux-dynamic.

The current Windows toolchain seems to use the /Z7 CXX compiler flag in both cases:

vcpkg/scripts/toolchains/windows.cmake

Lines 71 to 74 in 01f6021

	set(CMAKE_CXX_FLAGS_DEBUG "/D_DEBUG ${VCPKG_CRT_LINK_FLAG_PREFIX}d /Z7 /Ob0 /Od /RTC1 ${VCPKG_CXX_FLAGS_DEBUG}" CACHE STRING "")
	set(CMAKE_C_FLAGS_DEBUG "/D_DEBUG ${VCPKG_CRT_LINK_FLAG_PREFIX}d /Z7 /Ob0 /Od /RTC1 ${VCPKG_C_FLAGS_DEBUG}" CACHE STRING "")
	set(CMAKE_CXX_FLAGS_RELEASE "${VCPKG_CRT_LINK_FLAG_PREFIX} /O2 /Oi /Gy /DNDEBUG /Z7 ${VCPKG_CXX_FLAGS_RELEASE}" CACHE STRING "")
	set(CMAKE_C_FLAGS_RELEASE "${VCPKG_CRT_LINK_FLAG_PREFIX} /O2 /Oi /Gy /DNDEBUG /Z7 ${VCPKG_C_FLAGS_RELEASE}" CACHE STRING "")

Would the best option be to specify a custom triplet with a VCPKG_CXX_FLAGS_RELEASE option set to -g?

Note: This seems related to #17921, but I would like to know possible workarounds for this issue.

[kiwixz]

Would the best option be to specify a custom triplet with a VCPKG_CXX_FLAGS_RELEASE option set to -g?

Yes. You may also need the MSVC debug runtime flag (MTd or MDd).

[aristotelos]

OK, I tried this out and it doesn't seem to work with e.g. qt5-base, but that is probably because qt5-base uses QMake and does not map settings from CMake correctly. See #39140

[aristotelos]

Closed this issue because it was due to our custom VCPKG_CHAINLOAD_TOOLCHAIN_FILE that did not copy VCPKG_CXX_FLAGS properly as e.g. https://github.com/microsoft/vcpkg/blob/master/scripts/toolchains/linux.cmake#L79 does. I have now tested that this approach works for Linux.