$ ./factorVM 
Cannot resolve C library function
Symbol: gtk_init
Library: f
(U) Quotation: [ c-to-factor -> ]
    Word: c-to-factor
(U) Quotation: [ [ catchstack* push ] dip call -> catchstack* pop* ]
(O) Word: command-line-startup
(O) Method: M\ gtk-ui-backend (with-ui)
(U) Quotation: [
        OBJ-CURRENT-THREAD special-object error-thread set-global
        continuation -> error-continuation set-global
        [ original-error set-global ] [ rethrow ] bi
    ]