build error due to -Werror when building from git on Ubuntu 18.04

[Erik Auerswald]

Hi,

when trying to build GNU Coreutils from git on Ubuntu 18.04 I get the
following error:

    [...]
      CC       lib/acl-internal.o
    lib/acl-internal.c: In function 'free_permission_context':
    lib/acl-internal.c:479:1: error: function might be candidate for attribute 
'const' [-Werror=suggest-attribute=const]
     free_permission_context (struct permission_context *ctx)
     ^~~~~~~~~~~~~~~~~~~~~~~
    cc1: all warnings being treated as errors
    Makefile:9779: recipe for target 'lib/acl-internal.o' failed
    make[2]: *** [lib/acl-internal.o] Error 1
    [...]

    $ gcc --version
    gcc (Ubuntu 7.5.0-3ubuntu1~18.04) 7.5.0
    Copyright (C) 2017 Free Software Foundation, Inc.
    This is free software; see the source for copying conditions.  There is NO
    warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

I have (mostly) followed the instructions from README-hacking:

    git clone git://git.sv.gnu.org/coreutils coreutils-git
    cd coreutils-git
    ./bootstrap
    git submodule foreach git pull origin mastergit commit -m 'build: update 
gnulib submodule to latest' gnulib
    ./configure
    make

The build stops with the error message shown above.

Thanks,
Erik
-- 
Be water, my friend.
                        -- Bruce Lee