reading from tty's

["Jin S. Choi" <jsc@atype.com>]

I'm trying to read reliably from a port created by fork-pty-session
and having the following problem. Can anyone give me a hint as to
what's going on?

(define (test)
  (receive (process-object in-port out-port tty-name)
      (fork-pty-session (lambda () (run (/bin/echo "hello, world"))))
    (read-string 14 in-port) ; eat up text, CR/LF
    (read-char in-port))) ; one more

> (test)

Error: 5
       "I/O error"
       #{Procedure 8669 %fdport*-read-char}
       #{fdport-data}
1>