after struggling with this for over an hour, I think I finally found the problem. If I don't localize the filehandle, this problem goes away. Apparently, localizing that typeglob caused the underlying descriptor to disappear once the localized typeglob went out of scope.

Perhaps you should try one of the other filehandle related modules, to produce the filehandle (and assign to a scalar). For example: FileHandle, IO::Handle, or even gensym().

I remember having similar problems on an older perl, 5.005, and fixing it this way. Later perls didn't need it, <stroke>in part</stroke> mainly because they provide lexical filehandles... Until this.