Running Gurobi through Pyomo on Linux cluster - site module missing

Hello,

When I try to run the optimization code on a cluster (linux) I get the message: "ImportError: No module named site".

What is the reason for this error? I use Gurobi through Pyomo package in Python and miniconda distribution. 

I can see from the log that the model was successfully built and sent to the (Gurobi) solver, so the problem is probably with the solver itself. 

Dominik