Where is the precmd command in android?
If you are using Connectbot: according to an article at XDA-Developers, this is nothing but a cosmetical error:


  Connectbot seems to set shell variable 'PS1' to "$(precmd)$USER@$HOSTNAME:${PWD:-?} $ ".
  It means your shell (the busybox's ash applet) will try to use output from 'precmd' as a part of a command prompt.
  So when 'precmd' was not provided, error messages will be generated wenever a prompt was to be shown.


To fix this, mentioned post says you can use PS1="&gt; " (or simply unset PS1) to work around that error.