The Tcl example 'import' will not compile on Red Hat
Linux 7.0. It fails with this message, indicating
that there is probably a Makefile problem.
/usr/bin/ld: cannot find -lswigtcl8
collect2: ld returned 1 exit status
make: *** [tcl_cpp] Error 1
make: *** [all] Error 2
make: Target `check' not remade because of errors.