Probably bug in mps.sh version 3.3/Linux

In MPS 3.3 RC2, and also in RC1, the UNAME variable is not defined correctly, I get this error:

bin/mps.sh warning: Unknown operating system /bin/uname. Do not know how to add PWD to libraries path.

The solution for me has been to define UNAME=`uname` instead of UNAME=`which uname`

Bye,
Mar