bug report: tr (textutils v.2.0.21)

Here is testcase:
    ... download and build textutils-2.0.21 (*1) ...

    echo xyzt | ./src/tr 'xyzt' '----'
    ./src/tr: unrecognized option `----'
    Try `./src/tr --help' for more information.

    echo xyzt | ./src/tr 'xy' '--'
    ./src/tr: two strings must be given when translating

Apparently this tr mis-accepts SET2 for an option.

Yakov Lerner
--------------------

(*1)
    cd /tmp     
    wget ftp://alpha.gnu.org/gnu/textutils/textutils-2.0.21.tar.gz
    tar xzf textutils-2.0.21.tar.gz
    cd textutils-2.0.21; configure; make;