[Config]
exten => 1001, 1, DigitTimeout(2)
exten => 1001, 2, Answer()
exten => 1001, 3, Read(NUMBER,,3)
exten => 1001, 4, SayNumber(${NUMBER})
exten => 1001, 5, Goto(3)

[Console output]
pbx.c:6194 pbx_builtin_saynumber: SayNumber requires an argument(number)

; I using RHEL 3, but installed on VMware.
; I also test with *1.2.7.1 (but on real machine), it's OK.