[polari] build: Fail if gjs is not found

[Florian Müllner <fmuellner src gnome org>]

commit 59eccc5376665636876b49a0cf3c6335ded330b0
Author: Florian Müllner <fmuellner gnome org>
Date:   Tue Sep 3 18:43:06 2013 +0200

    build: Fail if gjs is not found
    
    We currently fail silently when gjs-1.0.pc is missing. Instead,
    directly check for gjs-console in PATH and fail if it is not found.

 configure.ac |    7 +++++--
 1 files changed, 5 insertions(+), 2 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 1211394..5aa45c7 100644
--- a/configure.ac
+++ b/configure.ac
@@ -22,8 +22,11 @@ PKG_CHECK_MODULES(POLARI,
                   gtk+-3.0 >= 3.9.12
                   telepathy-glib);
 
-GJS_CONSOLE=`$PKG_CONFIG --variable=gjs_console gjs-1.0`
-AC_SUBST(GJS_CONSOLE)
+AC_PATH_PROG([GJS_CONSOLE],[gjs-console],[no])
+
+if test "$GJS_CONSOLE" = "no"; then
+  AC_MSG_ERROR([gjs is required to build Polari])
+fi
 
 GLIB_COMPILE_RESOURCES=`$PKG_CONFIG --variable=glib_compile_resources gio-2.0`
 AC_SUBST(GLIB_COMPILE_RESOURCES)