Provide a more helpful error message when there is an autoconf version

mismatch;  backpatch.

diff --git a/configure.in b/configure.in
index a8529d397409b8a90d2f7346862b3accc004e0ee..8d8e0bc3b14cc0135499c9b6f99ca869b2bc3e22 100644 (file)
--- a/configure.in
+++ b/configure.in
@@ -19,7 +19,10 @@ m4_pattern_forbid(^PGAC_)dnl to catch undefined macros
 
 AC_INIT([PostgreSQL], [8.1.10], [[email protected]])
 
-m4_if(m4_defn([m4_PACKAGE_VERSION]), [2.59], [], [m4_fatal([Autoconf version 2.59 is required])])
+m4_if(m4_defn([m4_PACKAGE_VERSION]), [2.59], [], [m4_fatal([Autoconf version 2.59 is required.
+Untested combinations of 'autoconf' and PostgreSQL versions are not
+recommended.  You can remove the check from 'configure.in' but it is then
+your responsibility whether the result works or not.])])
 AC_COPYRIGHT([Copyright (c) 1996-2005, PostgreSQL Global Development Group])
 AC_CONFIG_SRCDIR([src/backend/access/common/heaptuple.c])
 AC_CONFIG_AUX_DIR(config)