[rygel] build: Fail configure if no tracker-sparql was not found

[Jens Georg <jensgeorg src gnome org>]

commit 6b75529d406eb5e8d9a8256de17bb9e2f4399ec5
Author: Jens Georg <mail jensge org>
Date:   Thu Jan 11 20:38:55 2018 +0100

    build: Fail configure if no tracker-sparql was not found

 configure.ac |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 00b94da..c51d580 100644
--- a/configure.ac
+++ b/configure.ac
@@ -427,6 +427,9 @@ AS_IF([test "x$enable_tracker_plugin" = "xyes"],
                                      tracker_api_version="VERSION"
                                    ])
                  ])
+    AS_IF([test "x:$trackerpkg" = "x:"],
+          [AC_MSG_ERROR([No supported API version of the tracker-sparql library was found])])
+
 
     PKG_CHECK_MODULES([RYGEL_PLUGIN_TRACKER_DEPS],
                       [$RYGEL_COMMON_MODULES gio-2.0 >= $GIO_REQUIRED ${trackerpkg}])