I have a C++ program that uses protobuf and asio, which compiles fine under Linux using g++. I am wondering how I could go about making a new preset which allows me to compile this program into a windows executable.

I have tried using mingw compiler, but it seems I do not understand how to use it properly.

This is my CmakePresets.json

{
    "version": 8,
    "configurePresets": [
        {
            "name": "debug",
            "displayName": "Debug",
            "description": "Using compiler: CXX = /usr/bin/g++",
            "binaryDir": "${sourceDir}/out/build/${presetName}",
            "cacheVariables": {
                "CMAKE_CXX_COMPILER": "/usr/bin/g++",
                "CMAKE_BUILD_TYPE": "Debug"
            }
        },
        {
            "name": "windows-debug",
            "displayName": "Windows Debug",
            "description": "Using compiler: CXX = /usr/bin/x86_64-w64-mingw32-g++",
            "binaryDir": "${sourceDir}/out/build/${presetName}",
            "cacheVariables": {
                "CMAKE_SYSTEM_NAME": "Windows",
                "CMAKE_CXX_COMPILER": "/usr/bin/x86_64-w64-mingw32-g++",
                "CMAKE_BUILD_TYPE": "Debug"
            }
        }
    ],
    "buildPresets": [
        {
            "name": "debug",
            "configurePreset": "debug"
        },
        {
            "name": "windows-debug",
            "configurePreset": "windows-debug"
        }
    ]
}

CMake generation fails because it can’t find “ZLIB::ZLIB”:

[main] Configuring project: dark-proxy 
[proc] Executing command: /usr/bin/cmake -DCMAKE_SYSTEM_NAME=Windows -DCMAKE_CXX_COMPILER=/usr/bin/x86_64-w64-mingw32-g++ -DCMAKE_BUILD_TYPE=Debug -S/home/burger/Desktop/dark-proxy -B/home/burger/Desktop/dark-proxy/out/build/windows-debug
[cmake] -- Could NOT find ZLIB (missing: ZLIB_LIBRARY) (found version "1.3")
[cmake] CMake Warning at /usr/local/lib/cmake/protobuf/protobuf-config.cmake:9 (find_package):
[cmake]   Found package configuration file:
[cmake] 
[cmake]     /usr/local/lib/cmake/absl/abslConfig.cmake
[cmake] 
[cmake]   but it set absl_FOUND to FALSE so package "absl" is considered to be NOT
[cmake]   FOUND.  Reason given by package:
[cmake] 
[cmake]   The following imported targets are referenced, but are missing:
[cmake]   protobuf::gmock
[cmake] 
[cmake] Call Stack (most recent call first):
[cmake]   protos/CMakeLists.txt:1 (find_package)
[cmake] 
[cmake] 
[cmake] -- Found Protobuf package with version : 29.0.0
[cmake] -- Configuring done (0.0s)
[cmake] CMake Error at /usr/local/lib/cmake/protobuf/protobuf-targets.cmake:70 (set_target_properties):
[cmake]   The link interface of target "protobuf::libprotobuf" contains:
[cmake] 
[cmake]     ZLIB::ZLIB
[cmake] 
[cmake]   but the target was not found.  Possible reasons include:
[cmake] 
[cmake]     * There is a typo in the target name.
[cmake]     * A find_package call is missing for an IMPORTED target.
[cmake]     * An ALIAS target is missing.
[cmake] 
[cmake] Call Stack (most recent call first):
[cmake]   /usr/local/lib/cmake/protobuf/protobuf-config.cmake:16 (include)
[cmake]   protos/CMakeLists.txt:1 (find_package)
[cmake] 
[cmake] 
[cmake] -- Generating done (0.0s)
[cmake] CMake Generate step failed.  Build files cannot be regenerated correctly.
[proc] The command: /usr/bin/cmake -DCMAKE_SYSTEM_NAME=Windows -DCMAKE_CXX_COMPILER=/usr/bin/x86_64-w64-mingw32-g++ -DCMAKE_BUILD_TYPE=Debug -S/home/burger/Desktop/dark-proxy -B/home/burger/Desktop/dark-proxy/out/build/windows-debug exited with code: 1

This is what the Cmake generation looks like when I use g++:

[main] Configuring project: dark-proxy 
[proc] Executing command: /usr/bin/cmake -DCMAKE_CXX_COMPILER=/usr/bin/g++ -DCMAKE_BUILD_TYPE=Debug -S/home/burger/Desktop/dark-proxy -B/home/burger/Desktop/dark-proxy/out/build/debug
[cmake] CMake Warning at /usr/local/lib/cmake/protobuf/protobuf-config.cmake:9 (find_package):
[cmake]   Found package configuration file:
[cmake] 
[cmake]     /usr/local/lib/cmake/absl/abslConfig.cmake
[cmake] 
[cmake]   but it set absl_FOUND to FALSE so package "absl" is considered to be NOT
[cmake]   FOUND.  Reason given by package:
[cmake] 
[cmake]   The following imported targets are referenced, but are missing:
[cmake]   protobuf::gmock
[cmake] 
[cmake] Call Stack (most recent call first):
[cmake]   protos/CMakeLists.txt:1 (find_package)
[cmake] 
[cmake] 
[cmake] -- Found Protobuf package with version : 29.0.0
[cmake] -- Configuring done (0.0s)
[cmake] -- Generating done (0.0s)
[cmake] -- Build files have been written to: /home/burger/Desktop/dark-proxy/out/build/debug

How do I use mingw to compile my project in the same way that g++ works to get a windows executable?