Merge branch 'use_subprocess.run' into merge

Author: syntron

OMPython/ModelicaSystem.py

@@ -303,7 +303,7 @@ def _run_cmd(self, cmd: list, timeout: Optional[int] = None):
             logger.debug("OM output for command %s:\n%s", cmd, stdout)
 
             if cmdres.returncode != 0:
-                raise ModelicaSystemError(f"Error running command {cmd}: nonzero return code")
+                raise ModelicaSystemError(f"Error running command {cmd}: return code = {cmdres.returncode}")
             if stderr:
                 raise ModelicaSystemError(f"Error running command {cmd}: {stderr}")
         except subprocess.TimeoutExpired: