我正在尝试从源代码在我的 Ubuntu 16.04 上构建一个 repo，一切顺利，直到它到达链接到 OpenCV 的文件。
我收到以下错误：
/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
所以我尝试检查链接器实际上在做什么。我输入了
ld - llibjpeg --verbose
并得到
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
正如我们所见，链接器没有查找正确的文件！另一方面，如果我输入
ld - ljpeg --verbose
我看到的是：
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
因此 libjpeg 库确实存在，链接器只是在寻找错误的文件。
在 makefile 中我有
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
pkg-config --cflags opencv并且shell脚本指示的路径pkg-config --libs opencv是正确的。
如有任何帮助我将不胜感激。
编辑：我make uninstall在 OpenCV 源文件夹中运行。之后，构建成功通过。非常奇怪，似乎 OpenCV 搞乱了符号链接。我之前玩过 opencv.pc 文件，但路径缺失或错误。
答案1
我不明白你哪里出了问题。我已经成功编译了它（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：
-L / usr / local / lib -lopencv_calib3d -lopencv_contrib -lopencv_core -lopencv_features2d -lopencv_flann -lopencv_gpu -lopencv_highgui -lopencv_imgproc -lopencv_legacy -lopencv_ml -lopencv_nonfree -lopencv_objdetect -lopencv_ocl -lopencv_photo -lopencv_stitching -lopencv_superres -lopencv_ts -lopencv_video -lopencv_videostab -lrt -lpthread -lm -ldl
和pkg-config --cflags opencv
-I /usr/本地/包括/opencv -I /usr/本地/包括