$ cat server.scm 
(use spiffy)

(root-path (current-directory))
(error-log (current-error-port))
(debug-log (current-error-port))


$ csi -s server
[Wed Nov 16 11:11:25 2011] "GET http://localhost:8080/foo.data HTTP/1.1" Error: (>)
bad argument type
#<procedure>

        Call history:

        g411412   
        close-input-port          
        raise     
        k465471   
        g512513516        
        g512513516        
        g469470   
        ##sys#signal      
        k668674   
        g569570577        
        g569570577        
        g571572578        
        g571572578        
        g672673   
        spiffy#handle-exception   
        with-output-to-string           <--


thread50: Closing off