Extension type encoding gif image/gif gz STRIP x-gzipSTRIP means that Spinner should strip this extension, and try again. Thus a file named spinner.tar.gz would get the Content-encoding 'x-gzip' and the Content-type 'application/unix-tar' instead of just the Content-encoding.
In Spinner 1.0b8 and later, you can include files by typing
#include <etc/extensions> #include <etc/more-ext>