如何修复Linker的断裂路径？

Question

我正试图从一个源代码在我的Ubuntu16.04上构建一个回购程序，一切都很顺利，直到它到达链接到OpenCV的文件为止。

我得到以下错误：

/usr/bin/ld: cannot find -lIlmImf
/usr/bin/ld: cannot find -llibjasper
/usr/bin/ld: cannot find -llibtiff
/usr/bin/ld: cannot find -llibpng
/usr/bin/ld: cannot find -llibjpeg
/usr/bin/ld: cannot find -lzlib
collect2: error: ld returned 1 exit status
Makefile:305: recipe for target 'lib/libmxnet.so' failed
make: *** [lib/libmxnet.so] Error 1

所以我试着检查链接器到底在做什么。我打字

ld - llibjpeg --verbose 

并得到了

attempt to open //usr/local/lib/x86_64-linux-gnu/liblibjpeg.so failed
attempt to open //usr/local/lib/x86_64-linux-gnu/liblibjpeg.a failed
attempt to open //lib/x86_64-linux-gnu/liblibjpeg.so failed
attempt to open //lib/x86_64-linux-gnu/liblibjpeg.a failed
attempt to open //usr/lib/x86_64-linux-gnu/liblibjpeg.so failed
attempt to open //usr/lib/x86_64-linux-gnu/liblibjpeg.a failed
attempt to open //usr/local/lib64/liblibjpeg.so failed
attempt to open //usr/local/lib64/liblibjpeg.a failed
attempt to open //lib64/liblibjpeg.so failed
attempt to open //lib64/liblibjpeg.a failed
attempt to open //usr/lib64/liblibjpeg.so failed
attempt to open //usr/lib64/liblibjpeg.a failed
attempt to open //usr/local/lib/liblibjpeg.so failed
attempt to open //usr/local/lib/liblibjpeg.a failed
attempt to open //lib/liblibjpeg.so failed
attempt to open //lib/liblibjpeg.a failed
attempt to open //usr/lib/liblibjpeg.so failed
attempt to open //usr/lib/liblibjpeg.a failed
attempt to open //usr/x86_64-linux-gnu/lib64/liblibjpeg.so failed
attempt to open //usr/x86_64-linux-gnu/lib64/liblibjpeg.a failed
attempt to open //usr/x86_64-linux-gnu/lib/liblibjpeg.so failed
attempt to open //usr/x86_64-linux-gnu/lib/liblibjpeg.a failed
ld: cannot find -llibjpeg

正如我们所看到的，链接器不是在寻找正确的文件！另一方面，如果我键入

ld - ljpeg --verbose 

我看到这个：

attempt to open //usr/local/lib/x86_64-linux-gnu/libjpeg.so failed
attempt to open //usr/local/lib/x86_64-linux-gnu/libjpeg.a failed
attempt to open //lib/x86_64-linux-gnu/libjpeg.so failed
attempt to open //lib/x86_64-linux-gnu/libjpeg.a failed
attempt to open //usr/lib/x86_64-linux-gnu/libjpeg.so succeeded
-ljpeg (//usr/lib/x86_64-linux-gnu/libjpeg.so)
libc.so.6 needed by //usr/lib/x86_64-linux-gnu/libjpeg.so
found libc.so.6 at //lib/x86_64-linux-gnu/libc.so.6
ld-linux-x86-64.so.2 needed by //lib/x86_64-linux-gnu/libc.so.6
found ld-linux-x86-64.so.2 at //lib/x86_64-linux-gnu/ld-linux-x86-64.so.2
ld: warning: cannot find entry symbol _start; not setting start address

所以libjpeg库就在那里，链接器只是在寻找一个错误的文件。

在我的makefile里

ifeq ($(USE_OPENCV), 1)
        CFLAGS += -DMXNET_USE_OPENCV=1 $(shell pkg-config --cflags opencv)
        LDFLAGS += $(filter-out -lopencv_ts, $(shell pkg-config --libs opencv))
        BIN += bin/im2rec

由shell脚本pkg-config --cflags opencv和pkg-config --libs opencv指示的路径是正确的。

如果能帮忙修理，我将不胜感激。

编辑:我在make uninstall源代码文件夹中运行OpenCV。之后，构建成功地通过了。很奇怪，好像是OpenCV搞砸了符号链接。我之前玩过opencv.pc文件，路径丢失或错误。

Answer 1

我不明白你哪里出问题了。我已经成功地编译了它(即使没有sudo apt-get build-dep libopencv-dev)：

wget https://github.com/opencv/opencv/archive/2.4.13.5.zip
unzip 2.4.13.5.zip
cd opencv-2.4.13.5
mkdir build
cd build
cmake ..
make -j16
sudo make install

然后pkg-config --libs opencv显示以下内容：

和pkg-config --cflags opencv

-I/usr/local/include/opencv -I/usr/local/include