In fact, it all came down to a typo. The advisor suggested the compiler and linker options citing the environment variable as ($MKLROOT). All I had to do was to remove the parentheses:
$ifort -i8 -I$MKLROOT/include/intel64/ilp64 -I$MKLROOT/include geevab.f90 $MKLROOT/lib/intel64/libmkl_lapack95_ilp64.a -Wl,--start-group $MKLROOT/lib/intel64/libmkl_intel_ilp64.a $MKLROOT/lib/intel64/libmkl_sequential.a $MKLROOT/lib/intel64/libmkl_core.a -Wl,--end-group -lpthread -lm -o geevabworked all right. Thanks for pointing this out.