(I think that this is an Emacs bug, rather than a Debian packaging bug.
I am using Emacs 26.1, amd64.)

In shell-mode, the command history can get confused by bash's syntax for
fd redirection, e.g. by "command 2> filename", and sometimes inserts a
space between the fd and the ">".

Here is a minimal example.

  $ emacs -q -nw
  M-x shell<ENTER>
  echo 2> /dev/null<ENTER>
  !echo<ENTER>
  M-p [to get the previous command in the history]

and the *shell* buffer looks like:

  $ echo 2> /dev/null

  $ !echo
  echo 2> /dev/null   [so far, so good]

  $ echo 2 > /dev/null  [that spells trouble!]

The problem is the space inserted between the "2" and the ">", which of
course changes the meaning of the command.