build: Require pkg.m4 >= 0.29 at bootstrap

diff --git a/configure.ac b/configure.ac
index 87cada07f8971a4617b9dd287b83e4aef374c353..fc17b25d84150d030afcedaac87ca46bef27168e 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -27,6 +27,8 @@ AM_INIT_AUTOMAKE([1.12 foreign subdir-objects])
 AM_SANITY_CHECK
 AM_MAINTAINER_MODE([enable])
 m4_ifdef([AM_SILENT_RULES],[AM_SILENT_RULES([yes])],)
+m4_ifdef([PKG_PREREQ], [PKG_PREREQ(0.29)],
+  [m4_fatal([pkg.m4 is too old; copy the latest version in build/m4])])
 
 dnl Enable platform specific extensions.
 AC_USE_SYSTEM_EXTENSIONS