Is there a convention for naming a gem with a prebuilt extension?  For
my gems I have chosen

"#{package}-#{version}-#{CONFIG["arch"]}-ruby#{CONFIG["MAJOR"]}#{CONFIG["MINOR"]}.gem"
e.g.,
mypackage-1.2.3-i686-linux-ruby18.gem
mypackage-1.2.3-i386-mswin32-ruby18.gem

One caveat is that mingw32 and mswin32 are binary compatible.  I would
also like to know if ruby 1.8.x versions are guaranteed binary
compatible.

This naming confuses remote installation, returning 404 Not Found for
both "gem -i packagename" and "gem -i <full name above>".  Presumably
"packagename-version.gem" naming is required.

There is the obvious (ugly) workaround of making arch part of the
package name.  Including arch in the package version is a "Malformed
version number" error.

Ideas?  Is there a plan to support prebuilt extensions?