I tested m4-1.4.18b and subsequent tarballs (with fixes included) on some platforms. Aside from - the problems reported here and in bug-gnulib, - a couple of gnulib unit tests that fail on some of the less important platforms,
the build went fine and all unit tests passed on: Linux x86_64: Ubuntu 16.04, CentOS 5,6,7,8, Fedora 13,33, openSUSE 15.2 Linux x86_64 with musl libc: Alpine Linux 3.13 Linux x64_64-x32 Linux i386: Ubuntu 16.04 Linux/arm64 Linux/arm64 with musl libc Linux/arm Linux/powerpc64le Linux/powerpc64le with musl libc Linux/powerpc 64-bit,32-bit Linux/s390x 64-bit,32-bit Linux/s390x with musl libc Linux/sparc 64-bit,32-bit Linux/mips 32,n32,64 Linux/ia64 Linux/hppa Linux/riscv64 Linux/alpha FreeBSD 12/x86_64 FreeBSD 12/i386 FreeBSD 13/arm64 NetBSD 8 64-bit,32-bit OpenBSD 6.9/x86_64 Hurd 2019 macOS 11/arm64 Solaris 10/x86_64 64-bit,32-bit Solaris 10/sparc 64-bit,32-bit Solaris 11.4/x86_64 64-bit,32-bit Solaris 11.3/sparc 32-bit Solaris 11 OmniOS 64-bit,32-bit Solaris 11 OpenIndiana 64-bit,32-bit AIX 7.1 64-bit,32-bit IRIX 6.5 Minix 3.3 Cygwin 2.9 In other words: Things look good. :-) Bruno