[SOLVED] how to choose specific lib while cross-compiling (using vcpkg and cmake)

Issue

I use vcpkg and cmake to do some cross-platform devlpment. After finishing an sample code at WSL,I tried to change my toolchain to arm-linux-gnueabihf,then it shows below.

[cmake]   Could not find a configuration file for package "plog" that is compatible
[cmake]   with requested version "".
[cmake] 
[cmake]   The following configuration files were considered but not accepted:
[cmake] 
[cmake]     /home/fuxiaoer/vcpkg/installed/x64-linux/share/plog/plogConfig.cmake, version: 1.1.9 (64bit)
[cmake] 
[cmake] Call Stack (most recent call first):
[cmake]   CMakeLists.txt:11 (find_package)
[cmake] 

where plog is a lib I try to use in this project.

then I remove plog:x64-linux.rebuild my project.it shows:

Could not find a package configuration file provided by "plog" with any of
[cmake]   the following names:
[cmake] 
[cmake]     plogConfig.cmake
[cmake]     plog-config.cmake

I tred to wriet an arm-linux-gnueabihf.cmake file for vcpkg at [vcpkgroot]/triplets/arm-linux-gnueabihf.cmake.

set(VCPKG_TARGET_ARCHITECTURE arm)
set(VCPKG_CMAKE_SYSTEM_NAME Linux)
set(VCPKG_CMAKE_SYSTEM_PROCESSOR arm)
set(VCPKG_CRT_LINKAGE dynamic)
set(VCPKG_LIBRARY_LINKAGE dynamic)

then use vcpkg install plog:arm-linux-gnueabihf to install a new lib which use arm-linux-gnueabihf to build and it worked. where /vcpkg/installed shows 3 folders

arm-linux-gnueabihf  vcpkg  x64-linux

When turn around to my cmake project,it shows same message like I mentioned before.it seems like cmake do not change its search path,and still use default path x64-linux to find

I added a new line at my cmakelists.txt to tell cmake where plog is.

set(plog_DIR "/home/fuxiaoer/vcpkg/installed/arm-linux-gnueabihf/share/plog")

then this project finally can build successfuly.that means the method I use worked.

my CMakeLists.txt is shown below.

cmake_minimum_required(VERSION 3.0.0)

project(cmake_with_ninja_and_vcpkg VERSION 0.1.0 LANGUAGES C CXX)

include(CTest)
enable_testing()

# set(plog_DIR "/home/fuxiaoer/vcpkg/installed/arm-linux-gnueabihf/share/plog")

find_package(Eigen3 CONFIG REQUIRED)
find_package(plog CONFIG REQUIRED)

add_executable(cmake_with_ninja_and_vcpkg main.cpp)

target_link_libraries(cmake_with_ninja_and_vcpkg PRIVATE Eigen3::Eigen)
target_link_libraries(cmake_with_ninja_and_vcpkg PRIVATE plog::plog)

set(CPACK_PROJECT_NAME ${PROJECT_NAME})
set(CPACK_PROJECT_VERSION ${PROJECT_VERSION})
include(CPack)

Solution

I tried to change my toolchain to arm-linux-gnueabihf

changing toolchains simply requires a clean reconfigure (meaning using a fresh folder or deleting the CMakeCache.txt). You cannot change vcpkg triplets without that.

it seems like cmake do not change its search path,and still use default path x64-linux to find

that is exactly what happens if you try to switch in an already configured project or forget to set VCPKG_TARGET_TRIPLET to the triplet you actually want to use. You might want to also set VCPKG_HOST_TRIPLET. Don't forget this needs to be defined before project()

Answered By - Alexander Neumann

Answer Checked By - Cary Denson (WPSolving Admin)