Crosscompilation project on Linux for Windows

I would like to compile C++ http server on my archlinux using drogon framework for Windows.
I read about possible way on official cmake docs:
https://cmake.org/cmake/help/book/mastering-cmake/chapter/Cross%20Compiling%20With%20CMake.html

I have installed all required mingw64-*** utilities and faced problem that after specialized -DCMAKE_TOOLCHAIN_FILE cmake no more can find Drogon package with find_package() command.

here is my main CMakeList.txt

cmake_minimum_required(VERSION 3.5)
project(lru_server CXX)

include(CheckIncludeFileCXX)

check_include_file_cxx(any HAS_ANY)
check_include_file_cxx(string_view HAS_STRING_VIEW)
check_include_file_cxx(coroutine HAS_COROUTINE)
if (NOT "${CMAKE_CXX_STANDARD}" STREQUAL "")
    # Do nothing
elseif (HAS_ANY AND HAS_STRING_VIEW AND HAS_COROUTINE)
    set(CMAKE_CXX_STANDARD 20)
elseif (HAS_ANY AND HAS_STRING_VIEW)
    set(CMAKE_CXX_STANDARD 17)
else ()
    set(CMAKE_CXX_STANDARD 14)
endif ()

set(CMAKE_CXX_STANDARD_REQUIRED ON)
set(CMAKE_CXX_EXTENSIONS OFF)

add_executable(${PROJECT_NAME} main.cpp)
target_include_directories(${PROJECT_NAME} PUBLIC
    lru_cache/
    endpoints/
)

target_sources( ${PROJECT_NAME} PUBLIC
    lru_cache/lru_cache.cpp
    endpoints/ApiController.cpp
)


find_package(Drogon CONFIG REQUIRED)
target_link_libraries(${PROJECT_NAME} PRIVATE Drogon::Drogon)


if (CMAKE_CXX_STANDARD LESS 17)
    # With C++14, use boost to support any, string_view and filesystem
    message(STATUS "use c++14")
    find_package(Boost 1.61.0 REQUIRED)
    target_link_libraries(${PROJECT_NAME} PUBLIC Boost::boost)
elseif (CMAKE_CXX_STANDARD LESS 20)
    message(STATUS "use c++17")
else ()
    message(STATUS "use c++20")
endif ()

aux_source_directory(controllers CTL_SRC)
aux_source_directory(filters FILTER_SRC)
aux_source_directory(plugins PLUGIN_SRC)
aux_source_directory(models MODEL_SRC)

drogon_create_views(${PROJECT_NAME} ${CMAKE_CURRENT_SOURCE_DIR}/views
                    ${CMAKE_CURRENT_BINARY_DIR})

target_include_directories(${PROJECT_NAME}
                           PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}
                                   ${CMAKE_CURRENT_SOURCE_DIR}/models)
target_sources(${PROJECT_NAME}
               PRIVATE
               ${SRC_DIR}
               ${CTL_SRC}
               ${FILTER_SRC}
               ${PLUGIN_SRC}
               ${MODEL_SRC})

also toolchain file:

# the name of the target operating system
set(CMAKE_SYSTEM_NAME Windows)

# which compilers to use for C and C++
set(CMAKE_C_COMPILER   x86_64-w64-mingw32-gcc)
set(CMAKE_CXX_COMPILER x86_64-w64-mingw32-g++)

# where is the target environment located
set(CMAKE_FIND_ROOT_PATH 
    /usr/x86_64-w64-mingw32    
    /usr/x86_64-w64-mingw32/lib
    /usr/lib
    /usr/lib/cmake
    /usr/lib/cmake/Drogon)

# adjust the default behavior of the FIND_XXX() commands:
# search programs in the host environment
# set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)

# search headers and libraries in the target environment
set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)

cmake -S /my_project_dir -B build-lru_server-MinGW64 -DCMAKE_TOOLCHAIN_FILE=/toolchain-mingw.cmake

without -DCMAKE_TOOLCHAIN_FILE all works (using clang++ compiller).

the cmake output error:

[20:01:45] @archlinux bin$ cmake -S /var/repo/lru_cpp_rest_server/lru_server -B /var/repo_build/lru_cpp_rest_server/build-lru_server-MinGW64 -DCMAKE_TOOLCHAIN_FILE=/var/repo/lru_cpp_rest_server/lru_server/TC-mingw.cmake
CMake Warning (dev) at CMakeLists.txt:29 (target_sources):
  Policy CMP0076 is not set: target_sources() command converts relative paths
  to absolute.  Run "cmake --help-policy CMP0076" for policy details.  Use
  the cmake_policy command to set the policy and suppress this warning.

  An interface source of target "lru_server" has a relative path.
This warning is for project developers.  Use -Wno-dev to suppress it.

CMake Error at CMakeLists.txt:42 (find_package):
  Could not find a package configuration file provided by "Drogon" with any
  of the following names:

    DrogonConfig.cmake
    drogon-config.cmake

  Add the installation prefix of "Drogon" to CMAKE_PREFIX_PATH or set
  "Drogon_DIR" to a directory containing one of the above files.  If "Drogon"
  provides a separate development package or SDK, be sure it has been
  installed.

Why when i using toolchain drogon and other installed on system files not foundable?

UPD:
after advices from @Tsyvarev

[22:19:01] alxndrklbk@archlinux bin$ cmake -S /var/repo/lru_cpp_rest_server/lru_server/ -B build-lru_server-MinGW-Debug -DCMAKE_TOOLCHAIN_FILE=/var/repo/lru_cpp_rest_server/lru_server/TC-mingw.cmake
-- The CXX compiler identification is GNU 12.2.0
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: /usr/bin/x86_64-w64-mingw32-gcc - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Looking for C++ include any
-- Looking for C++ include any - found
-- Looking for C++ include string_view
-- Looking for C++ include string_view - found
-- Looking for C++ include coroutine
-- Looking for C++ include coroutine - not found
CMake Warning (dev) at CMakeLists.txt:29 (target_sources):
  Policy CMP0076 is not set: target_sources() command converts relative paths
  to absolute.  Run "cmake --help-policy CMP0076" for policy details.  Use
  the cmake_policy command to set the policy and suppress this warning.

  An interface source of target "lru_server" has a relative path.
This warning is for project developers.  Use -Wno-dev to suppress it.

-- Found Jsoncpp: /usr/x86_64-w64-mingw32/include  
CMake Error at /usr/share/cmake/Modules/FindPackageHandleStandardArgs.cmake:230 (message):
  Could NOT find OpenSSL, try to set the path to OpenSSL root folder in the
  system variable OPENSSL_ROOT_DIR (missing: OPENSSL_CRYPTO_LIBRARY
  OPENSSL_INCLUDE_DIR)
Call Stack (most recent call 

I've successfully cross-compiled your project with quasi-msys2 (which I'm the author of).

It takes care of the toolchain file, so you don't need to write one yourself.

• First, install quasi-msys2 prerequisites (this is for Ubuntu 22.04, adjust for Arch):

  sudo apt install make wget tar zstd gpg wine
  # Install Clang and LLD
  bash -c "$(wget -O - https://apt.llvm.org/llvm.sh)"
  

  Note Clang, I'm going to be using it instead of GCC for this.

• Then install quasi-msys2, and the necessary packages from it:

  git clone https://github.com/HolyBlackCat/quasi-msys2
  cd quasi-msys2 
  make install _gcc _jsoncpp _zlib _openssl
  env/shell.sh
  cd ..
  

  Here we install MSYS2 GCC for the libraries it provides. Also, since Drogon is not in MSYS2 packages, we have to build it ourselves, and need to install its dependencies: jsoncpp, zlib, openssl.

• Clone Drogon:

  git clone https://github.com/drogonframework/drogon
  cd drogon
  git submodule update --init --recursive
  cd ..
  

• Patch out their bugs:

  • Rename headers and libraries to lowercase, since our setup is case-sensitive, unlike native Windows:

    find drogon -type f -exec sed -i -E 's/(Windows.h|WinSock2.h|Rpc.h|Rpcrt4|Crypt32|Secur32)/\L/g' {} +
    

  • Add missing headers:

    (echo -e '#include <dirent.h>\n#include <sys/stat.h>'; cat drogon/trantor/trantor/utils/AsyncFileLogger.cc) | sponge drogon/trantor/trantor/utils/AsyncFileLogger.cc
    

• Build Drogon:

  CXXFLAGS='-Wno-defaulted-function-deleted -Wno-unqualified-std-cast-call -Wno-inconsistent-missing-override' cmake -S drogon -B drogon-build
  cmake --build drogon-build -j`nproc`
  cmake --install drogon-build
  

  Here we silence a few Clang warnings here.

  We also install the resulting library into our quasi-msys2 installation. Normally I would advise against this, since this mixes your files with those from msys2 packages.

  But it makes things easier. And you can quickly reset quasi-msys2 to a clean state using make reinstall-all, if you mess something up.

• Lastly, clone and build your project:

  git clone https://github.com/AlxndrKlbk/lru_cpp_rest_server
  cmake -S lru_cpp_rest_server/lru_server/ -B lru_server-build
  cmake --build lru_server-build -j`nproc`
  

• And run it (this uses Wine):

  lru_server-build/lru_server.exe 
  

Reported issues:

• https://github.com/an-tao/trantor/issues/267
• https://github.com/an-tao/trantor/issues/268
• https://github.com/drogonframework/drogon/issues/1655
• https://github.com/drogonframework/drogon/issues/1656