printf comes from the (chicken format) module, which is not imported. Looks like a mistake in the site.
https://api.call-cc.org/5/doc/chicken/format/printf $ csi -n CHICKEN (c) 2008-2022, The CHICKEN Team (c) 2000-2007, Felix L. Winkelmann Version 5.4.1 (rev 268dfc88) linux-unix-gnu-x86-64 [ 64bit dload ptables ] Type ,? for help. #;1> printf Error: unbound variable: printf #;1> (import chicken.format) ; loading /home/siiky/.local/lib/chicken/11/chicken.format.import.so ... #;2> printf #<procedure (chicken.format#printf fstr . args)>
