Bump autoconf version bound to >= 2.69

Reviewers: hvr

Subscribers: rwbarton, thomie, erikd, carter

GHC Trac Issues: #14910

Differential Revision: https://phabricator.haskell.org/D4495

configure.ac

@@ -55,13 +55,14 @@ AC_SUBST([release], [1])
 # First off, a distrib sanity check..
 AC_CONFIG_SRCDIR([mk/config.mk.in])
 
-dnl * We require autoconf version 2.60
-dnl We need 2.50 due to the use of AC_SYS_LARGEFILE and AC_MSG_NOTICE.
-dnl We need 2.52 due to the use of AS_TR_CPP and AS_TR_SH.
-dnl Using autoconf 2.59 started to give nonsense like this
-dnl  #define SIZEOF_CHAR 0
-dnl recently.
-AC_PREREQ([2.60])
+dnl * We require autoconf version 2.69 due to
+dnl   https://bugs.ruby-lang.org/issues/8179. Also see #14910.
+dnl * We need 2.50 due to the use of AC_SYS_LARGEFILE and AC_MSG_NOTICE.
+dnl * We need 2.52 due to the use of AS_TR_CPP and AS_TR_SH.
+dnl * Using autoconf 2.59 started to give nonsense like this
+dnl     #define SIZEOF_CHAR 0
+dnl   recently.
+AC_PREREQ([2.69])
 
 # -------------------------------------------------------------------------
 # Prepare to generate the following header files

distrib/configure.ac.in

@@ -6,6 +6,9 @@ dnl
 
 AC_INIT([The Glorious Glasgow Haskell Compilation System], [@ProjectVersion@], [glasgow-haskell-bugs@haskell.org], [ghc-AC_PACKAGE_VERSION])
 
+dnl See /configure.ac for rationale.
+AC_PREREQ([2.69])
+
 dnl--------------------------------------------------------------------
 dnl * Deal with arguments telling us gmp is somewhere odd
 dnl--------------------------------------------------------------------

libraries/integer-gmp/configure.ac

-AC_PREREQ(2.60)
+AC_PREREQ(2.69)
 AC_INIT([Haskell integer (GMP)], [1.0], [libraries@haskell.org], [integer])
 
 # Safety check: Ensure that we are in the correct source directory.