Why do I get Illegal instruction when running my code?

Problem

You may encounter the following error message at runtime:

Illegal instruction (core dumped)

Solution

The system on which you have compiled your code have a different architecture with respect to the compute nodes of the system where you are trying to run your executable.

The Cray compiler wrappers provided by the programming environment on Cray systems will cross-compile your code in order to run on the compute nodes.