usage: ./pkgtool.sh [-a nt32|nt64] [-b debug|release] [-i|-m <dname> -M <dname>|-r|-R|-t] [-v]
                    [<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 <dname>        Setup package archives mirror in <dname> and/or
        -M <dname>        Setup Git repositories mirror in <dname>
        -r                List reverse dependencies of single named package.
        -R                List recursive reverse dependencies of single named package.
        -t                Produce tarball of package build root directory and build log
                          file for the purpose of distribution given build failure.
        -v                Increase verbosity.

        <variable name>=<variable override>[ ..]
                          Override build or package variable.