When loading a session file from another machine Iget errors of the formE518: Unknown option: balloonexpr=Which is one of the more obscure features of Vim that Idont seem to have compiled in. However, grepping theoutput of Vims configure script doesnt show anydirectly related compile flag.What does one have to do to enable the balloonexproption? This is on Vim version patch 8.0.0134.
Which compile flag enables balloonexpr?
installing
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-evalAccording 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_BEVALi.e. basically when you use a supported Gui + the eval feature. 