[oe] rootfs_tar.bbclass not found?

[Jeff Rush]

Hopefully a trivial question.

Objective: I am trying to generate a tarball of an executable program, the
helloworld.bb program, for installation onto a system that lacks support for
ipk files.

To get a tarball package, I add to my local.conf:

   INHERIT += "package_tar package_ipk"

but when I do:

   bitbake helloworld

or indeed any target, I get the following error during the parse stage:

ERROR: Could not inherit file classes/rootfs_tar.bbclass while parsing
/home/jeff/Projects/OpenEmbedded/openembedded/recipes/images/slugos-image.bb

This error is repeated for every *-image.bb file parsed.  The reason is
because the file classes/image.bbclass has this line at the top of the file:

  inherit rootfs_${IMAGE_PKGTYPE}

so it is looking for "rootfs_tar.bbclass" but the only rootfs-*.bbclass files
that exist are:

  classes/rootfs_deb.bbclass
  classes/rootfs_ipk.bbclass
  classes/rootfs_rpm.bbclass

So building an image from tar'd packages is not support - fine, because in
this case I really do not want to build an image, just a single helloworld.tar
package.  But I cannot get past the parsing phase because of this problem.

What can I add to my local.conf to 'short circuit' this logic related to the
building of images?

Thanks for helping out a newbie,

-Jeff