在 MacOS 上未找到 openssl/conf.h 文件错误答案

【问题标题】：openssl/conf.h file not found error on MacOS在 MacOS 上未找到 openssl/conf.h 文件错误
【发布时间】：2022-07-18 15:32:41
【问题描述】：

尝试编译代码（使用 cmake）时，我不断收到此错误：

In file included from /usr/local/include/cpprest/http_client.h:68:
In file included from /usr/local/include/boost/asio/ssl.hpp:18:
In file included from /usr/local/include/boost/asio/ssl/context.hpp:23:
In file included from /usr/local/include/boost/asio/ssl/context_base.hpp:19:
/usr/local/include/boost/asio/ssl/detail/openssl_types.hpp:23:10: fatal error: 'openssl/conf.h' file not found
#include <openssl/conf.h>
         ^~~~~~~~~~~~~~~~
1 error generated.
make[2]: *** [CMakeFiles/httpclient.dir/http_client.cpp.o] Error 1
make[1]: *** [CMakeFiles/httpclient.dir/all] Error 2
make: *** [all] Error 2

我尝试关注这些链接，但没有任何帮助： Fatal Error: 'openssl/conf.h' file not found 和 'openssl/conf.h' file not found error on on MacOS Big Sur 和 'openssl/conf.h' file not found error on MacOS Sierra

以下是我的 cmake ：

cmake_minimum_required(VERSION 3.9)

find_package(cpprestsdk REQUIRED)

set (CMAKE_CXX_STANDARD 11)

add_executable(httpclient http_client.cpp)

set(OPENSSL_ROOT_DIR /usr/local/opt/openssl@3)
#set(OPENSSL_LIBRARIES /usr/local/opt/openssl@3/lib)
set(OPENSSL_ROOT_DIR /usr/local/opt/openssl@3/*)
set(OPENSSL_LIBRARIES /usr/local/opt/openssl@3/lib)
include(FindOpenSSL)

target_include_directories(httpclient INTERFACE ${OPENSSL_ROOT_DIR}/include)

target_link_libraries(httpclient PRIVATE cpprestsdk::cpprest
                                         openssl)

我也尝试过设置 LDFLAGS 和 CPPFLAGS，但没有帮助。还尝试重新安装 boost - 不起作用。

请帮助我了解如何解决此问题。

谢谢！

【问题讨论】：

标签： macos c++11 boost cmake openssl

【解决方案1】：

我也面临同样的问题。这是我的 CMakeLists.txt：

cmake_minimum_required(VERSION 3.22)
project(Test)

set(CMAKE_CXX_STANDARD 14)

set(OPENSSL_ROOT_DIR /usr/local/opt/openssl) # it points to openssl@3

find_package(Boost COMPONENTS system filesystem REQUIRED)

find_package(cpprestsdk REQUIRED)

add_executable(Test main.cpp)
target_link_libraries(
    Test
        PRIVATE Boost::system
        PRIVATE Boost::filesystem
)

这里是 C++ 测试代码（Boost 教程代码）：

#include <ctime>
#include <iostream>
#include <string>
#include <boost/asio.hpp>
#include <cpprest/http_msg.h> // the code can be compiled with this "include"
// #include <cpprest/http_client.h> // compilation with this "include" ends with the same openssl error

using boost::asio::ip::tcp;

std::string make_daytime_string()
{
    using namespace std; // For time_t, time and ctime;
    time_t now = time(0);
    return ctime(&now);
}

int main() {
    std::cout << "Ahoj" << std::endl;
    try
    {
        boost::asio::io_context io_context;

        tcp::acceptor acceptor(io_context, tcp::endpoint(tcp::v4(), 13));

        for (;;)
        {
            tcp::socket socket(io_context);
            acceptor.accept(socket);

            std::string message = make_daytime_string();

            boost::system::error_code ignored_error;
            boost::asio::write(socket, boost::asio::buffer(message), ignored_error);
        }
    }
    catch (std::exception& e)
    {
        std::cerr << e.what() << std::endl;
    }

    return 0;
}

操作系统： macOS Monterey 12.4 XCODE： 13.4.1 构建工具：忍者 IDE： CLion 2022.1.3

顺便说一句。根据https://github.com/microsoft/cpprestsdk 文档，cmake 配置对于 cpprestsdk 来说是极简的，但它在 mac 上不起作用（在 windows 上也是一个问题 - cpprestsdk 包 -> #include -> 构建错误 C2338 static_assert failed : '不支持从流中提取类型')。

【讨论】：