cygport problem with pkg name starting with number

[Marco Atzeri <marco.atzeri@gmail.com>]

It is not a huge number of case as we have only two packages
in this category 4ti2 and 2048-cli

on   /usr/share/cygport/lib/pkg_pkg.cygpart

there is this code using indirect variable assignment
as ${!dbg_contents_var}

------------------------------------------------------------------
         local dbg_contents_var=${PN//[-+\.]/_}_debuginfo_CONTENTS;

         __step "${PN}-debuginfo-${PVR}.tar.xz";
         mkdir -p ${distdir}/${PN}/${PN}-debuginfo;
         tar Jcvf 
${distdir}/${PN}/${PN}-debuginfo/${PN}-debuginfo-${PVR}.tar.xz \
             usr/*/debug/ ${autoloaddir} ${!dbg_contents_var} \
             | tee ${T}/.${PN}-debuginfo.lst \
             || error "Debuginfo package creation failed: ${PN}-debuginfo"

------------------------------------------------------------------

that produces

/usr/share/cygport/lib/pkg_pkg.cygpart: line 197: 
4ti2_debuginfo_CONTENTS: bad substitution

Any idea how to overcome the issue in cygport code ?

Of course I can just rename the package lib4ti2 and solve the issue ;-)


Regards
Marco