The MKL link line advisor usually displays the link line with several instances of $MKLROOT. Today, while using it, I found that it gave this link line:
$MKLroot/libmkl_scalapack_core.a -Wl,--start-group $MKLroot/libmkl_intel.a $MKLroot/libmkl_intel_thread.a $MKLroot/libmkl_core.a $MKLROOT/libmkl_blacs_openmpi.a -Wl,--end-group -openmp -lpthread
Note that both "MKLroot" and "MKLROOT" are shown. I suggest that only uppercase be used; at any rate only one shell variable should be used, not two that differ by case.
The choices that gave this line are