[emacs-w3m:13249] Re: Build errors - bad fd number

In [emacs-w3m:13248]
On Sat, 23 Feb 2019 08:28:34 +0000, Colin Baxter wrote:
> After cloning emacs-w3m git repository, I get a bad fd number error.

> Output of `autoconf <RET>':

> /usr/bin/m4:configure.in:5: non-numeric argument to builtin `substr'
> /usr/bin/m4:configure.in:7: non-numeric argument to builtin `substr'
[...]
> I'm using:
> emacs-26.1; Autoconf version 2.13; m4 macro processor version 1.4.17.

I tried autoconf-2.13 and confirmed that the same error happens.
But it's quite old (1999).  Isn't there any chance to upgrade it?
I'm using autoconf 2.69 (2012).

Regards,