build: Set minimum Automake version to 1.13 #18290

This PR suggests to set the required minimum Automake version to 1.13 explicitly for the following reasons:

• it guarantees that CVE-2012-3386 has been fixed
• AC_CONFIG_MACRO_DIR macro support, which we already use; from the release notes:

Improvements to aclocal and related rebuilds rules:

• Autoconf-provided macros AC_CONFIG_MACRO_DIR and AC_CONFIG_MACRO_DIRS are now traced by aclocal, and can be used to declare the local m4 include directories. Formerly, one had to specify it with an explicit '-I' option to the 'aclocal' invocation.

• AM_SILENT_RULES macro support (since version 1.11)

Automake 1.13 requires Autoconf 2.65 or greater. We already have 2.69 since #17769.

For reference, Automake 1.13 was released in December of 2012.

CentOS 7 uses Automake 1.13.4

See the Automake docs for more info:

• AM_INIT_AUTOMAKE
• List of Automake options

Concept ACK

Concept ACK

ACK ddc7e42d600a0cb3e763cda0dc04a1f2f34e9440 - I think adding a minimum required version here is fine. I'd be surprised if someone who is currently building Bitcoin Core was unable to after this change.

I had a quick look to check that operating systems we support (even those older than we do) have at least automake >=1.13.x:

Alpine 3.9: 1.16.1
Debian 7: 1.14.1
Ubuntu 14.04: 1.14.1
Fedora 30: 1.16.1
OpenBSD 6.0: 1.15
FreeBSD 11: 1.16.1
NetBSD 7: 1.16.1

To address the points in the PR description:

it guarantees that CVE-2012-3386 has been fixed

This is a locally exploitable race, which requires you to already be sharing a filesystem with the attacker when you run make distcheck.

AC_CONFIG_MACRO_DIR macro support, which we already use;

I'm not quite sure why you've highlighted this. UsingAC_CONFIG_MACRO_DIR works fine when using automake <1.13, as long as you're passing -I build-aux/m4 to aclocal. Which we do i.e: Makefile.am.

I tested on OpenBSD that using automake 1.12.6 works with master (b5c7665e3083f5daaf2b9f247a59a008f2d689a4). It blows up if you remove -I build-aux/m4:

export AUTOMAKE_VERSION=1.12 
bazinga# ./autogen.sh                                                                                                 
libtoolize: putting auxiliary files in AC_CONFIG_AUX_DIR, `build-aux'.
libtoolize: copying file `build-aux/ltmain.sh'
....
libtoolize: copying file `build-aux/m4/ltversion.m4'
libtoolize: copying file `build-aux/m4/lt~obsolete.m4'
libtoolize: Consider adding `-I build-aux/m4' to ACLOCAL_AMFLAGS in Makefile.am.
configure.ac:236: error: possibly undefined macro: AC_MSG_ERROR
      If this token and others are legitimate, please use m4_pattern_allow.
      See the Autoconf documentation.
configure.ac:322: error: possibly undefined macro: AC_LANG_PROGRAM
configure.ac:518: error: possibly undefined macro: AC_CHECK_LIB
configure.ac:1251: error: possibly undefined macro: PKG_CHECK_MODULES
configure.ac:1277: error: possibly undefined macro: AC_CHECK_HEADER
autoreconf-2.69: /usr/local/bin/autoconf-2.69 failed with exit status: 1

Concept ACK on setting a minimum automake version. No opinion on which one, though looking at @fanquake's list 1.13 seems to be acceptable. so also ACK ddc7e42d600a0cb3e763cda0dc04a1f2f34e9440