【问题标题】：Cmake doesn't see variable from find_pathCmake 看不到 find_path 中的变量
【发布时间】：2016-10-13 15:50:33
【问题描述】：

我正在尝试使用带有 cmake 和 gcc 5.4 的 activemq-cpp 编译代码

find_path(ACTIVEMQCPP_DIR NAMES cms/Config.h HINTS $ENV{ACTIVEMQDIR})

这里ACTIVEMQDIR是一个环境变量设置为

/usr/local/include/activemq-cpp-3.10.0

message(STATUS ACTIVEMQCPP_DIR=${ACTIVEMQCPP_DIR})

include_directories(${ACTIVEMQCPP_DIR})

//include_directories(/usr/local/include/activemq-cpp-3.10.0) 如果我明确地硬编码路径，那么没关系...

cmake 的输出：

-- The C compiler identification is GNU 5.4.0
-- The CXX compiler identification is GNU 5.4.0
-- Check for working C compiler: /usr/bin/cc
-- Check for working C compiler: /usr/bin/cc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Detecting C compile features
-- Detecting C compile features - done
-- Check for working CXX compiler: /usr/bin/c++
-- Check for working CXX compiler: /usr/bin/c++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- 1=/usr/local/include/activemq-cpp-3.10.0
-- 2=/usr/local/lib
-- 3=/usr/local/include/activemq-cpp-3.10.0
-- 4=/usr/local/lib/libactivemq-cpp.so
-- Configuring done
-- Generating done
-- Build files have been written to
    -- The C compiler identification is GNU 5.4.0
    -- The CXX compiler identification is GNU 5.4.0
    -- Check for working C compiler: /usr/bin/cc
    -- Check for working C compiler: /usr/bin/cc -- works
    -- Detecting C compiler ABI info
    -- Detecting C compiler ABI info - done
    -- Detecting C compile features
    -- Detecting C compile features - done
    -- Check for working CXX compiler: /usr/bin/c++
    -- Check for working CXX compiler: /usr/bin/c++ -- works
    -- Detecting CXX compiler ABI info
    -- Detecting CXX compiler ABI info - done
    -- Detecting CXX compile features
    -- Detecting CXX compile features - done

ACTIVEMQCPP_DIR=/usr/local/include/activemq-cpp-3.10.0

    -- Configuring done
    -- Generating done
    -- Build files have been written to: /home/oem/ClionProjects/untitled/b2

问题是include_directories(${ACTIVEMQCPP_DIR}) 不起作用。变量ACTIVEMQCPP_DIR 未设置

【问题讨论】：

注释ACTIVEMQCPP_DIR= 行是什么，用LARGE粗体字体显示？ CMake输出的第二部分（缩进）是什么意思？它与第一部分非常相似（未缩进）。请修复问题帖子的内容和格式。目前很难理解。

标签： c++ cmake

【解决方案1】：

这样写 include_directories($ENV{ACTIVEMQCPP_DIR}) 这样cmake knows it's an environemnt variable.

【讨论】：