[asterisk-users] [1.4.39.1/AGI] ast_carefulwrite: write() returned error: Broken pipe

[Gilles]

Hello

	Incoming calls from the FXO trigger an AGI script which simply NOOP
data sent by Asterisk through stdin.

The first two NOOP work fine, but after this, Asterisk isn't happy:

============= extensions.conf
...
[from_fxo]
exten => s,1,Wait(2)
exten => s,n,Set(CID=${CALLERID(num)})
exten => s,n,AGI(/var/tmp/test.lua)
exten => s,n,Wait(5)
exten => s,n,Hangup

============= /var/tmp/test.lua
#!/usr/bin/lua

--Must empty stdin for CHANNEL STATUS to work
while true do
        local line = io.read()
        if line == "" then break end
        io.write("NOOP ",line,"\n")
end

============= Console
centos*CLI>
    -- Starting simple switch on 'DAHDI/1-1'
    -- Executing [s at from_fxo:1] Wait("DAHDI/1-1", "2") in new stack
    -- Executing [s at from_fxo:2] Set("DAHDI/1-1", "CID=123465") in new
stack
    -- Executing [s at from_fxo:3] AGI("DAHDI/1-1", "/var/tmp/test.lua")
in new stack
    -- Launched AGI Script /var/tmp/test.lua
AGI Tx >> agi_request: /var/tmp/test.lua
AGI Tx >> agi_channel: DAHDI/1-1
AGI Tx >> agi_language: en
AGI Tx >> agi_type: DAHDI
AGI Tx >> agi_uniqueid: 1298367207.9
AGI Tx >> agi_callerid: 0177628460
AGI Tx >> agi_calleridname: unknown
AGI Tx >> agi_callingpres: 0
AGI Tx >> agi_callingani2: 0
AGI Tx >> agi_callington: 0
AGI Tx >> agi_callingtns: 0
AGI Tx >> agi_dnid: unknown
AGI Tx >> agi_rdnis: unknown
AGI Tx >> agi_context: from_fxo
AGI Tx >> agi_extension: s
AGI Tx >> agi_priority: 3
AGI Tx >> agi_enhanced: 0.0
AGI Tx >> agi_accountcode:
AGI Tx >>
AGI Rx << NOOP agi_request: /var/tmp/test.lua
AGI Tx >> 200 result=0
AGI Rx << NOOP agi_channel: DAHDI/1-1
AGI Tx >> 200 result=0
[Feb 22 10:33:30] ERROR[5444]: utils.c:967 ast_carefulwrite: write()
returned error: Broken pipe
AGI Rx << NOOP agi_language: en
AGI Tx >> 200 result=0
[Feb 22 10:33:30] ERROR[5444]: utils.c:967 ast_carefulwrite: write()
returned error: Broken pipe
=================

Has someone experienced the same thing? Am I doing it wrong, or is
1.4.39.1 broken and I should downgrade to a known, good build?

Thank you.