It's not really a tmux issue. You can demonstrate it just by invoking a shell.
For example, if you "cd /tmp" and then invoke a new shell with "bash -l", the code in /etc/profile will cd to your home directory. (This doesn't happen on Ubuntu, for example, which has a different /etc/profile.) But if you invoke bash without "-l", or with "CHERE_INVOKING=1 bash -l", the new shell will have /tmp as its current directory. "chere" is a script, installable via Cygwin setup, that enables opening a Cygwin terminal in a specific directory via the Windows Explorer context menu (right-click). I haven't tried it myself yet. Here's the relevant code from /etc/profile : # Make sure we start in home unless invoked by CHERE if [ ! -z "${CHERE_INVOKING}" ]; then unset CHERE_INVOKING else cd "${HOME}" || echo "WARNING: Failed attempt to cd into ${HOME}!" fi -- Problem reports: https://cygwin.com/problems.html FAQ: https://cygwin.com/faq/ Documentation: https://cygwin.com/docs.html Unsubscribe info: https://cygwin.com/ml/#unsubscribe-simple