找不到-lpython2:MatCaffe安装错误

在构建MatCaffe（Caffe的Matlab包装器）的过程中，我面临以下错误：

[ 96%] Built target convert_mnist_data
[ 96%] Built target convert_mnist_siamese_data
[ 98%] Built target pycaffe
[100%] Building Matlab interface: /home/trunks/Downloads/caffe-master/matlab/+caffe/private/caffe_.mexa64
Building with 'g++'.
Warning: You are using gcc version '4.8.2'. The version of gcc is not supported. The version currently supported with MEX is '4.7.x'. For a list of currently supported compilers see: http://www.mathworks.com/support/compilers/current_release.
Warning: You are using gcc version '4.8.2-19ubuntu1)'. The version of gcc is not supported. The version currently supported with MEX is '4.7.x'. For a list of currently supported compilers see: http://www.mathworks.com/support/compilers/current_release.
/usr/bin/ld: cannot find -lpython2
collect2: error: ld returned 1 exit status

make[2]: *** [../matlab/+caffe/private/caffe_.mexa64] Error 255
make[1]: *** [matlab/CMakeFiles/matlab.dir/all] Error 2
make: *** [all] Error 2

仔细检查后，我发现使用以下命令，以下文件导致了上述错误：

 grep -rnw "./" -e "-lpython2"

它向我透露了以下情况：

./matlab/CMakeFiles/matlab.dir/build.make:53:   cd /home/trunks/Downloads/caffe-master/build/matlab && /usr/local/MATLAB/R2014a/bin/mex -output /home/trunks/Downloads/caffe-master/matlab/+caffe/private/caffe_.mexa64 /home/trunks/Downloads/caffe-master/matlab/+caffe/private/caffe_.cpp -DCPU_ONLY -DWITH_PYTHON_LAYER -DGTEST_USE_OWN_TR1_TUPLE -I/home/trunks/Downloads/caffe-master/src -I/usr/include -I/home/trunks/Downloads/caffe-master/build/external/glog-install/include -I/home/trunks/Downloads/caffe-master/build/external/gflags-install/include -I/home/trunks/Downloads/caffe-master/build/include -I/usr/local/include/opencv -I/usr/local/include -I/usr/include/python2.7 -I/home/trunks/anaconda/lib/python2.7/site-packages/numpy/core/include -I/home/trunks/Downloads/caffe-master/include -I/home/trunks/Downloads/caffe-master/build -L/home/trunks/Downloads/caffe-master/build/lib -L/usr/lib/x86_64-linux-gnu -L/home/trunks/Downloads/caffe-master/build/external/gflags-install/lib -L/home/trunks/Downloads/caffe-master/build/external/glog-install/lib -L/usr/lib -L/usr/local/lib -L/usr/local/lib -L/usr/local/lib -L/usr/local/lib -lcaffe -lboost_system -lboost_thread -lpthread -lgflags -lglog -lhdf5_hl -lhdf5 -llmdb -lleveldb -lsnappy -lopencv_core -lopencv_highgui -lopencv_imgproc -lopencv_imgcodecs -lopenblas -lpython2 -lboost_python -lprotobuf

因此，我将对应的-lpython2更改为-lpython2.7，希望能够解决这个问题。但是没有屈服

我还尝试了以下方法：

./matlab/CMakeFiles/matlab.dir/build.make:53:   cd /home/trunks/Downloads/caffe-master/build/matlab && /usr/local/MATLAB/R2014a/bin/mex -output /home/trunks/Downloads/caffe-master/matlab/+caffe/private/caffe_.mexa64 /home/trunks/Downloads/caffe-master/matlab/+caffe/private/caffe_.cpp -DCPU_ONLY -DWITH_PYTHON_LAYER -DGTEST_USE_OWN_TR1_TUPLE -I/home/trunks/Downloads/caffe-master/src -I/usr/include -I/home/trunks/Downloads/caffe-master/build/external/glog-install/include -I/home/trunks/Downloads/caffe-master/build/external/gflags-install/include -I/home/trunks/Downloads/caffe-master/build/include -I/usr/local/include/opencv -I/usr/local/include -I/usr/include/python2.7 -I/home/trunks/anaconda/lib/python2.7/site-packages/numpy/core/include -I/home/trunks/Downloads/caffe-master/include -I/home/trunks/Downloads/caffe-master/build -L/home/trunks/Downloads/caffe-master/build/lib -L/usr/lib/x86_64-linux-gnu -L/home/trunks/Downloads/caffe-master/build/external/gflags-install/lib -L/home/trunks/Downloads/caffe-master/build/external/glog-install/lib -L/usr/lib -L/usr/local/lib -L/usr/local/lib -L/usr/local/lib -L/usr/local/lib -lcaffe -lboost_system -lboost_thread -lpthread -lgflags -lglog -lhdf5_hl -lhdf5 -llmdb -lleveldb -lsnappy -lopencv_core -lopencv_highgui -lopencv_imgproc -lopencv_imgcodecs -lopenblas -lpython2 -lboost_python -lprotobuf

删除cmakcache.txt并执行make。但它没有起作用

我在/cmake master中编辑了默认的CMakeLists.txt文件，以更改一些默认设置。我发现Caffe中CMakeLists.txt中的默认python版本设置为2

//指定要使用的python版本 python_版本：STRING=2.7

我将其更改为2，并在一个新的构建文件夹中重复整个configure-generate-make过程。但是没有屈服。每次相同的matlab/build.make文件显示-lpython2时，将其直接更改为2.7不会产生任何效果

我试图查看matlab/build.make文件，但在那里找不到任何与此错误直接相关的内容

---

任何坚实的帮助都将不胜感激。我在Ubuntu 14.04上使用Matlab2014a。

根据错误消息和命令，导致它的原因是，python库似乎安装在不寻常的位置，因此

ld

（链接器）无法在其默认路径中找到它。由于CMake脚本已经找到了头文件，它还应该设置

mex

可执行文件，以便使用库本身，但由于某些原因，它没有这样做

---

使构建包工作的最简单方法是将

LD_LIBRARY\u PATH

设置到python库所在的目录，然后运行

make

。如果您想修复CMake脚本，这可能会对您有所帮助。

感谢@Tsyvarev提供的答案。我找到了一个相当简单的解决办法。我刚刚创建了一个符号链接（libpython2.so），它指向/usr/lib文件夹中的libpython2.7.so。这就解决了问题。libpython2.7.so也出现在/usr/lib中，所以我不认为这是一个异常安装的问题。

我也有同样的问题。绝望中，我刚刚从

build matlab/matlab/CMakeFiles/matlab.dir/build.make中删除了
-lpython2

这是因为Utils.cmake中的
caffe\u parse\u linker\u libs
函数中有一个bug，该函数将类似于
/usr/lib/x86\u 64-linux-gnu/libpython2.7的内容转换为
-lpython2

这可以通过替换（在cmake/Utils.cmake中）来解决

与

elseif(IS_ABSOLUTE ${lib})
  get_filename_component(folder  ${lib} PATH)
  get_filename_component(filename ${lib} NAME)
  string(REGEX REPLACE "\\.[^.]*$" "" filename_without_shortest_ext ${filename})

  string(REGEX MATCH "^lib(.*)" __match ${filename_without_shortest_ext})
  list(APPEND libflags -l${CMAKE_MATCH_1})
  list(APPEND folders    ${folder})
else()

更新后的函数正确地将
/usr/lib/x86_64-linux-gnu/libpython2.7.so
转换为
-lpython2.7
我遇到了这个问题，它的根源似乎是Cmake无法获得不同版本的python，例如“libpython.so.1.0”。我将cmakcache.txt文件改为“libpython.so”，问题就解决了。不仅是python，我的“cudnn”也有这个问题，这个解决方案解决了这个问题