ImportError: libaruco.so.3.0: cannot open shared object file: No such file or directory

[mingliangfu]

I am running an Ubuntu 16.04 machine with python 3.6.4, Anaconda 5.0.1. A virtual environment named py36 was created with Anaconda for my project. I have completed the installation following the Installation Python3 (experimental). In order to accommodate the system environment, setup.py was edited as follows:

from distutils.core import setup, Extension
sourcefiles = ['aruco_wrap.cxx']
aruco_module = Extension('_aruco',
sources=sourcefiles,
language="c++",
extra_compile_args=["-std=c++11", "-Wall", "-fopenmp", "-Wunused-variable"],
include_dirs=["/usr/local/include/opencv2", "/home/*/anaconda3/envs/py36/include/eigen3", "."],
libraries=["opencv_core", "opencv_imgproc", "opencv_calib3d", "opencv_highgui", "aruco"],
library_dirs=["/usr/local/lib","/home/*/programs/aruco304/install/lib","/home/*/anaconda3/envs/py36/lib"])

setup(name='aruco', version='3.0', author="""ArUco: Rafael Muñoz Salinas, Python wrappers: Marcus Degenkolbe""", description="""ArUco Python wrappers""", ext_modules=[aruco_module], py_modules=["aruco"], )

After the installation, the corresponding .so and .py files (titled as _aruco.cpython-36m-x86_64-linux-gnu.so and aruco.py) were generated in the path--/home/*/anaconda3/envs/py36/lib/python3.6/site-packages. When the program was acitvated, an issue appeared:
ImportError: libaruco.so.3.0: cannot open shared object file: No such file or directory

In fact, no file named as libaruco.so.3.0 was generated during the installation. I tried to make a link file by ln -s path/to/virtual/environment/_aruco.cpython-36m-x86_64-linux-gnu.so path/to/virtual/environment/libaruco.so.3.0. But it didn't work.

[mingliangfu]

According to the tip in Test, I added the build library location LD_LIBRARY_PATH=/home/*/programs/python-aruco3/build/lib.linux-x86_64-3.6 to .bashrc. Unfortunately, it didn't work.

[fehlfarbe]

The generated wrapper library _aruco.cpython-36m-x86_64-linux-gnu.so depends on libaruco.so.3.0 which contains the ArUco stuff. libaruco.so.3.0 is created by compiling the ArUco lib (step 2: download, compile and install ArUco: http://www.uco.es/investiga/grupos/ava/node/26). So for your installation it should be in /home/*/programs/aruco304/install/lib or after make install in /usr/local/lib.

[mingliangfu]

Hi @fehlfarbe , thanks for your attention and tips. I tried to add the ArUco lib location /home/*/programs/aruco304/install/lib to /.bashrc. Regrettably, the same issue still be around. I tried to make a link file by ln -s /home/*/programs/aruco304/install/lib/libaruco.so.3.0.4 /home/*/anaconda3/envs/py36/lib/python3.6/site-packages/libaruco.so.3.0. It failed for a second time. But what's baffling, the generated aruco lib files are indeed located in the path--/home/*/programs/aruco304/install/lib.

[fehlfarbe]

Mh that's really weird...what's the output of ldd _aruco.cpython-36m-x86_64-linux-gnu.so?
Is the path to aruco.so really in $LD_LIBRARY_PATH? Just check with echo $LD_LIBRARY_PATH.
Is the symlink valid? Check with ls -l /home/*/anaconda3/envs/py36/lib/python3.6/site-packages/libaruco.so.3.0.

Maybe just recompile the wrapper?! Does installation via pip (pip install aruco) work in your virtualenv?

[mingliangfu]

THX for your continued support. Under the installation path--/home/*/programs/python-aruco3, the output of ldd are listed partly as follows:
...
libopencv_core.so.3.0 => /usr/local/lib/libopencv_core.so.3.0 (0x00007f66a21cc000)
libaruco.so.3.0 => /home/*/programs/aruco304/install/lib/libaruco.so.3.0 (0x00007f66a087c000)
...
libglib-2.0.so.0 => /home/*/anaconda3/envs/py36/lib/libglib-2.0.so.0 (0x00007f669d8be000)
libXdamage.so.1 => /usr/lib/x86_64-linux-gnu/libXdamage.so.1 (0x00007f669a8a4000)
...

Then, check the LD_LIBRARY_PATH:
/home/*/torch/install/lib:/home/*/freenect2/lib:/usr/local/lib:/usr/local/cuda/lib64:/home/*/programs/aruco304/install/lib:/home/*/anaconda3/envs/py36/lib/python3.6/site-packages:

Clearly, the aruco lib path has been included in LD_LIBRARY_PATH. Finally, the log output of the symlink is: 08:29 /home/*/anaconda3/envs/py36/lib/python3.6/site-packages/libaruco.so.3.0 -> /home/*/programs/aruco304/install/lib/libaruco.so.3.0.4. Thus, the link is still valid.

After the above checking, the issue is still around. During another attempt of reinstallation, output log of the terminal is : Requirement already satisfied: aruco in ./anaconda3/envs/py36/lib/python3.6/site-packages . However, the reinstallation didn't make a difference.

OK, I meant to leave it here for now. Thanks for your kind help again!