/usr/bin/expect_timed-read is in expect 5.45-7+deb9u1.
This file is owned by root:root, with mode 0o755.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 | #!/bin/sh
# -*- tcl -*-
# The next line is executed by /bin/sh, but not tcl \
exec tclsh8.6 "$0" ${1+"$@"}
package require Expect
# read a complete line from stdin
# aborting after the number of seconds (given as an argument)
# - Don Libes
set timeout $argv
expect -re \n {send_user $expect_out(buffer)}
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