Re: groff: error after update of gnulib, 13th January 2023

[Bruno Haible]

Bjarni Ingi Gislason wrote:
> ../lib/openat-die.c:37:3: warning: implicit declaration of function 'error'; 
> did you mean 'strerror'? [-Wimplicit-function-declaration]
>    37 |   error (exit_failure, errnum,
> ...
>   "error.h" is a local file with:
> 
> // -*- C++ -*-
> /* Copyright (C) 1989-2020 Free Software Foundation, Inc.
>      Written by James Clark (jjc@jclark.com)
> [...]
> class errarg {

The 'openat-die' module depends on the 'error' module
https://www.gnu.org/software/gnulib/MODULES.html#module=error

So you now have a conflict between Gnulib's error.h (which is
meant to make glibc's error.h portable) and groff's error.h.

Also, at link time, some linkers might be confused between the error.o
file from Gnulib (which is meant to contain glibc compatible error()
and error_at_line() functions) and groff's error.o.

What has changed between yesterday and today is that, in VPATH builds,
Gnulib's error.h was in the source directory and is now in the build
directory. Depending on the order of -I options the other error.h
is now visible.

Bruno