The kibitz script, which is a part of expect, has the path
to the write program hard-coded as /bin/write.  write is
actually found in /usr/bin/write, so kibitz breaks unless
/usr/bin/write is symlinked to /bin/write (or the script
is changed).  Using expect-5.26-20 and util-linux-2.8-11,
kibitz prints "sh: /bin/write: no such file or directory".
(I'm submitting this as a util-linux bug, though it's
really an expect bug, because there is no category for
expect bugs.)