'make clean' not working

[Andrea Monaco]

Hello,


I'm trying to rebuild a bison-3.8 release tree, but "make clean" aborts
with this error:


CDPATH="${ZSH_VERSION+.}:" && cd . && /bin/bash 
'/root/bison-3.8/build-aux/missing' autoconf
/root/bison-3.8/build-aux/missing: line 81: autoconf: command not found
WARNING: 'autoconf' is missing on your system.
         You should only need it if you modified 'configure.ac',
         or m4 files included by it.
         The 'autoconf' program is part of the GNU Autoconf package:
         <https://www.gnu.org/software/autoconf/>
         It also requires GNU m4 and Perl in order to run:
         <https://www.gnu.org/software/m4/>
         <https://www.perl.org/>
Makefile:3894: recipe for target 'configure' failed
make: *** [configure] Error 127


Is it expected? I don't think I modified configure.ac or any m4 file, so
autoconf shouldn't be needed. Also, I think it's unusual in any case to
require autotools for a basic operation such as make clean.

I'm on a recent GNU/Hurd release, if it's important.



Thanks,

Andrea Monaco