pub fn popup_cmd(launcher: &str, small: bool) -> StringExpand description
#{pane_id} in there is inert on purpose: display-popup expands no format
in the command it runs, so bare like this the shell drops it as a comment and
the picker asks tmux which pane it was opened from. Quoting it would hand the
picker the format itself as a string.
-e TAIMUX_POPUP=1 is how the picker knows it is IN a popup rather than
inline in a pane, which decides whether it may reopen itself on a resize. It
is set here rather than guessed over there because every guess available (our
size against the active pane’s, a leaked $TMUX_PANE) is wrong for some real
layout, and guessing wrong means an inline picker closing itself and coming
back as a popup.