[ostree] build: Also add a configure check for YACC/bison

[Colin Walters <walters src gnome org>]

commit 73d77a21932fb8defe244505284ee31ecf13ed43
Author: Colin Walters <walters verbum org>
Date:   Mon Dec 7 10:39:37 2015 -0500

    build: Also add a configure check for YACC/bison
    
    So we error out more nicely if not found.

 configure.ac |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 41a4aa0..1135ff6 100644
--- a/configure.ac
+++ b/configure.ac
@@ -42,6 +42,9 @@ AM_CONDITIONAL(BUILDOPT_INSTALL_TESTS, test x$enable_installed_tests = xyes)
 
 AC_CHECK_HEADER([sys/xattr.h],,[AC_MSG_ERROR([You must have sys/xattr.h from glibc])])
 
+AC_CHECK_PROGS(YACC, 'bison -y', :)
+AS_IF([test "$YACC" = :], [AC_MSG_ERROR([bison not found but required])])
+
 PKG_PROG_PKG_CONFIG
 
 GIO_DEPENDENCY="gio-unix-2.0 >= 2.40.0 libgsystem >= 2015.1"