Comment 5 for bug 1670749

This is also affecting me still in snapcraft 3.7:
When snap is run in classic mode root is the same as the host system so paths need to be specified in the environment. This will also affect dynamic link library search (I've seen this happen in a different project), at compile time the path for the library is set relative to the prime directory and, as root is not the prime directory in classic mode, search fails.

confinement: classic
apps:
  netman:
    environment:
      PATH: ${SNAP}/usr/bin:${PATH}
      PYTHONPATH: ${SNAP}/usr/lib/python3.6
    command: python3 netman/index.py