Missing items in LD_LIBRARY_PATH break numpy stage-packages

[Artur Glavic]

When trying to build a python project that used numpy by adding python3-numpy to stage-packages the import fails because libblas.so.3 and liblapack.so.3 cannot be found. The libraries are included in the snap package bud their path isn't searched during execution.

I could work around it by adding these lines to my snapcraft.yaml file:
    environment:
      LD_LIBRARY_PATH: $LD_LIBRARY_PATH:$SNAP/usr/lib/x86_64-linux-gnu/blas:$SNAP/usr/lib/x86_64-linux-gnu/lapack

My setup is:
- VirtualBox running Ubuntu Eoan (x86_64)
- Latest snapcraft from snap
- Using lxd based build

I assume the issue is that these libraries use a sub-directory and thus this could be a general issue in the packaging process of libraries.

The issue doesn't come up when using numpy from python-packages, but this is no option when using complex dependencies like wxpython that need binary packages and depend on numpy.