'undefined symbol: cblas_sgemm' error when running mnist example

[sunshineatnoon]

Hi, I have successfully build mxnet and install python package, but when I try to run the mnist example:

python example/mnist/mlp.py

I got this error:

Traceback (most recent call last):
  File "example/mnist/mlp.py", line 2, in <module>
    from data import mnist_iterator
  File "/home/xuetingli/Documents/dmlc/mxnet/example/mnist/data.py", line 9, in <module>
    import mxnet as mx
  File "/usr/lib/python2.7/site-packages/mxnet-0.5.0-py2.7.egg/mxnet/__init__.py", line 7, in <module>
    from .base import MXNetError
  File "/usr/lib/python2.7/site-packages/mxnet-0.5.0-py2.7.egg/mxnet/base.py", line 43, in <module>
    _LIB = _load_lib()
  File "/usr/lib/python2.7/site-packages/mxnet-0.5.0-py2.7.egg/mxnet/base.py", line 35, in _load_lib
    lib = ctypes.cdll.LoadLibrary(lib_path[0])
  File "/usr/lib64/python2.7/ctypes/__init__.py", line 438, in LoadLibrary
    return self._dlltype(name)
  File "/usr/lib64/python2.7/ctypes/__init__.py", line 360, in __init__
    self._handle = _dlopen(self._name, mode)
OSError: /usr/lib/python2.7/site-packages/mxnet-0.5.0-py2.7.egg/mxnet/libmxnet.so: undefined symbol: cblas_sgemm

I'm on CentOS 7 and I have installed blas and atblas via:

sudo yum install blas blas-devel atlas atlas-devel

Does anyone know how to solve this? Thx!

[tqchen]

This is likely due to an linker error. Try to change the BLAS options in config.mk to atlas, or blas to see what works for you

[sunshineatnoon]

@tqchen Do I need to change the variable USE_BLAS to the path of my atblas or do I have to add a new variable USE_BLAS_PATH to my atblas path?

[tqchen]

I think only changing USE_BLAS should be fine. As lonng as the atlas is in LD_LIBRARY_PATH

[sunshineatnoon]

I changed the config.mk file like this:

# choose the version of blas you want to use
# can be: mkl, blas, atlas, openblas
USE_STATIC_MKL = NONE
USE_BLAS = atlas

Then set the LD_LIBRARY_PATH to /usr/lib4/atlas
But when I rebuild mxnet, I got this error:

/usr/bin/ld: cannot find -lcblas
collect2: error: ld returned 1 exit status
make: *** [lib/libmxnet.so] Error 1

[tqchen]

You might also want to set LIBRARY_PATH as well. LD_LIBRARY_PATH is used for runtime search of libraries, LIBRARY_PATH is used for compile time search

[sunshineatnoon]

Tried this too, no luck:

export LIBRARY_PATH=/usr/lib64/atlas

I also tried openblas, which I installed at /usr/local/lib and /usr/local/include, this time the make command doesn't give me any error, but when running the mnist example, I still get this error:

OSError: /usr/lib/python2.7/site-packages/mxnet-0.5.0-py2.7.egg/mxnet/libmxnet.so: undefined symbol: cblas_sgemm

[sunshineatnoon]

By using Openblas and running cd python; python setup.py develop --user again, now I can run the mnist example. Thanks for your help~

[raymondtay]

Hi guys, i'm using this mxnet and ran into this same incident; was wondering if there was a note on that, would be very helpful