How to Set Path Environment Variable using CMake and Visual Studio to Run Test

For setting custom project setting in Visual Studio from CMake you can use a XML file as a template which can be configured from CMake to work as the .user file.
At my work we use this to set custom debug parameters.

Check the directory containing the generated .vcxproj files for the user settings in the .user files. Here is a snippet of an example UserTemplate.vcxproj.user file we use.

    <?xml version="1.0" encoding="Windows-1252"?>
      <VisualStudioUserFile
        ProjectType="Visual C++"
        Version="9.00"
        ShowAllFiles="false"
        >
        <Configurations>
            <Configuration
                Name="Debug|@USERFILE_PLATFORM@"
                >
                <DebugSettings
                    Command="@USERFILE_COMMAND_DEBUG@"
                    WorkingDirectory="@USERFILE_WORKING_DIRECTORY_DEBUG@"
                    CommandArguments="@USERFILE_COMMAND_ARGUMENTS_DEBUG@"
                    Attach="false"
                    DebuggerType="3"
                    Remote="1"
                    RemoteMachine="@USERFILE_REMOTE_MACHINE_DEBUG@"
                                <!-- More settings removed for snippet -->
                />
            </Configuration>
                <!-- Rest of Configurations -->

Another example of a UserTemplate.vcxproj.user to set the PATH variable, would be:

    <?xml version="1.0" encoding="utf-8"?>
    <Project ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
      <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">
        <LocalDebuggerEnvironment>PATH=..\Your_path;%PATH%".</LocalDebuggerEnvironment>
        <DebuggerFlavor>WindowsLocalDebugger</DebuggerFlavor>
      </PropertyGroup>
    </Project>

Setting the UserTemplate.vcxproj.user file next to your CMakeLists.txt file, you can inject any needed variables from CMake into the .vcxproj.user file of your builded project. In CMake you can set the appropiate CMake variables (and add more in the template file if you need them). Next you can do something like this to configure the file.

    # Find user and system name
    SET(SYSTEM_NAME $ENV{USERDOMAIN} CACHE STRING SystemName)
    SET(USER_NAME $ENV{USERNAME} CACHE STRING UserName)

    # Configure the template file
    SET(USER_FILE ${_projectName}.vcxproj.${SYSTEM_NAME}.${USER_NAME}.user)
    SET(OUTPUT_PATH ${CMAKE_CURRENT_BINARY_DIR}/${USER_FILE})
    CONFIGURE_FILE(UserTemplate.vcxproj.user${USER_FILE} @ONLY)

If you don't care about the system and the user name, the following configuration would be enough.

    # Configure the template file
    SET(USER_FILE ${_projectName}.vcxproj.user)
    SET(OUTPUT_PATH ${CMAKE_CURRENT_BINARY_DIR}/${USER_FILE})
    CONFIGURE_FILE(UserTemplate.vcxproj.user ${USER_FILE} @ONLY)

Just spotted this question now. To debug cmake files I use

MESSAGE( STATUS "static text ${variable}" )

I have never had to set the path get my tests to run. Are you using CTest? It looks like the link you are following is used with ctest.

If I was trying to get this to work I would use set_tests_properties explicitly first.

set_tests_properties(SomeTest PROPERTIES ENVIRONMENT "PATH=c:\somedir;c:\otherdir")

Then make it more general.

You can give any options globally with the new VS_USER_PROPS target property (version >= 3.8).

Here is a working example:

CMakeLists.txt

cmake_minimum_required(VERSION 3.0)

project(SetEnvPathTest)

file(WRITE main.cpp [=[
// http://en.cppreference.com/w/cpp/utility/program/getenv
#include <iostream>
#include <cstdlib>

int main()
{
    if(const char* env_p = std::getenv("PATH"))
        std::cout << "Your PATH is: " << env_p << '\n';
}
]=])
add_executable(${PROJECT_NAME} main.cpp)

file(WRITE "${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}.Cpp.user.props" [=[
<?xml version="1.0" encoding="utf-8"?> 
<Project DefaultTargets="Build" ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
    <LocalDebuggerEnvironment>PATH=C:\Test</LocalDebuggerEnvironment>
  </PropertyGroup>
  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
    <LocalDebuggerEnvironment>PATH=C:\Test</LocalDebuggerEnvironment>
  </PropertyGroup>
</Project>
]=])

set_target_properties(
    ${PROJECT_NAME}
    PROPERTIES
        VS_USER_PROPS "${PROJECT_NAME}.Cpp.user.props"
) 

References

• CMake Issue #8884: Set Visual Studio project "custom environment variables" setting with CMake
• set diagnostics:caret from CMakeLists.txt