Which compile flag enables “balloonexpr”?

Question

When loading a session file from another machine I get errors of the form

E518: Unknown option: balloonexpr=

Which is one of the more obscure features of Vim that I don’t seem to have compiled in. However, grepping the output of Vim’s configure script doesn’t show any directly related compile flag.

What does one have to do to enable the balloonexpr option? This is on Vim version patch 8.0.0134.

Btw. someone powerful enough please create the tags balloonexpr and compile-options, thanks. — Philipp Gesang, Dec 25 '16 at 12:07

score 2 · Accepted Answer · answered Dec 25 '16 at 20:17

That feature is shown by the 'balloon-eval' flag in the :version output. See :h +feature-list for the description of all flags and specifically :h balloon-eval

According to feature.h it is enabled for the following conditions:

  #if (defined(FEAT_GUI_MOTIF) || defined(FEAT_GUI_ATHENA) \
          || defined(FEAT_GUI_GTK) || defined(FEAT_GUI_W32)) \
          && (   ((defined(FEAT_TOOLBAR) || defined(FEAT_GUI_TABLINE)) \
                  && !defined(FEAT_GUI_GTK) && !defined(FEAT_GUI_W32)) \
              || defined(FEAT_SUN_WORKSHOP) \
              || defined(FEAT_NETBEANS_INTG) || defined(FEAT_EVAL))
  # define FEAT_BEVAL

i.e. basically when you use a supported Gui + the eval feature.

Which compile flag enables “balloonexpr”?

1 Answers1