Display a warning if configuring without any UI.

diff --git a/configure.ac b/configure.ac
index 755d911fba6d30315bb4b73a2af2a611173769fe..3709434eab484a2df416a31b6ea7bfe311e7fba8 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -110,3 +110,9 @@ AC_CHECK_PROGS([OPTIPNG], [optipng])
 
 AC_CONFIG_FILES([Makefile])
 AC_OUTPUT
+
+have_ui=false
+AM_COND_IF([HAVE_MOTIF], [have_ui=:])
+AS_IF([$have_ui], [],
+[AC_MSG_WARN([No user interface is enabled.])
+AC_MSG_WARN([It will not be possible to play the game.])])