usage: ./pkgtool.sh [-a nt32|nt64] [-b debug|release] [-i|-m <dname1>,<dname2>|-r|-s|-t]

                    [<variable name>=<variable override>[ ..]] name

        -a nt32|nt64          Selects 32-bit or 64-bit architecture; defaults to nt64.

        -b debug|release      Selects debug or release build kind; defaults to debug.

        -i                    List package variables and dependencies of single named package.

        -m <dname1>,<dname2>  Setup package archives mirror in <dname1> and Git repositories mirror in <dname2>

        -r                    List reverse dependencies of single named package.

        -s                    Enter interactive package build shell environment for single

                              named package; requires a package dump file. If the package

                              has not been built yet or built successfully, it will be rebuilt

                              at build steps up until, by default, the `build' build step and

                              forcibly aborted and dumped prior to enterting the shell.

        -t                    Produce tarball of package build root directory and build log

                              file for the purpose of distribution given build failure.

        <variable name>=<variable override>[ ..]

                              Override build variable.