[Chicken-users] Error: unbound variable: read-line

[Daniel Beecham]

$ cat read.ss
(let ((s (read-line))) (print s))

$ csc read.ss

$ ./read

Error: unbound variable: read-line

    Call history:

    read.ss:1: read-line    <--

$ csi read.ss
[...]

; loading read.ss ...

<input>

<input>

#;1> <C-d>

$ chicken --version
[...]

Version 4.8.0.3 (Stability/4.8.0) (rev 091c3d9)

linux-unix-gru-x86-64 [ 64bit manyargs dload ptables ]
compiled 2013-03-13 on aeryn.xorinia.dim (Darwin)
[...]

Any ideas why this might be happening?