FTBFS 3.5.6-1build1 with gcc-11

[Bryce Harrington]

https://people.canonical.com/~doko/ftbfs-report/test-rebuild-20210805-impish-impish.html#ubuntu-server

https://launchpadlibrarian.net/552666442/buildlog_ubuntu-impish-amd64.postfix_3.5.6-1build1_BUILDING.txt.gz

In file included from attr_clnt.c:88:
/usr/include/unistd.h:363:13: error: conflicting types for ‘closefrom’; have ‘void(int)’
  363 | extern void closefrom (int __lowfd) __THROW;
      | ^~~~~~~~~
In file included from attr_clnt.c:87:
./sys_defs.h:1512:12: note: previous declaration of ‘closefrom’ with type ‘int(int)’
 1512 | extern int closefrom(int);
      | ^~~~~~~~~
make: *** [Makefile:210: attr_clnt.o] Error 1

Builds fine with gcc-10 (c.f. https://launchpadlibrarian.net/544878816/buildlog_ubuntu-impish-amd64.postfix_3.5.6-1build1_BUILDING.txt.gz) but fails using gcc-11.

[Bryce Harrington (bryce)]

Seen by redhat and fixed in postfix-3.5.9-11.el9: https://bugzilla.redhat.com/show_bug.cgi?id=1984045.

"closefrom is a new function in glibc 2.34. It follows the Solaris precedent, so it returns void (not int). At the minimum, Postfix needs to adjust its return type. The only caller of the function does not use the returned value anyway."

Fedora's patch attached, I've not tested it yet.

[Miriam España Acebal (mirespace)]

Hi Bryce,

I used the patch for LP#1885403 (also I found it at gentoo), and the build is ok. Attached is the log corresponding to that build. I hope it helps.

[Utkarsh Gupta (utkarsh)]

Hi Miriam,

Could you please sneak in this fix (if not already) with the other bug you're working on? TIA!

[Launchpad Janitor (janitor)]

This bug was fixed in the package postfix - 3.5.6-1ubuntu2

---------------
postfix (3.5.6-1ubuntu2) impish; urgency=medium

  * d/rules: Removed LDFLAG -Bsymbolic-functions (LP: #1885403).
  * d/p/postfix-3.6.2-glibc-234-build-fix.patch: Fix for building
    against glibc-2.34 (LP: #1939353).

 -- Miriam España Acebal <email address hidden> Thu, 02 Sep 2021 13:04:29 +0200

[Scott Kitterman (kitterman)]

Incorporation of this patch in postfix upstream is currently being discussed on the postfix-users mailing list. The specific question asked by Wietse is:

Has this been adopted, or do people on 3.5.* still have to tinker with
their /etc/resolv.conf files?

If anyone from Ubuntu could comment on that, it would be great.

[Bryce Harrington (bryce)]

@Scott, yes we're carrying it in Ubuntu. There is also user confirmation for the patch at https://marc.info/?l=postfix-users&m=162811639914512&w=2. Do you know if the issue affects Debian yet? Would it be worth forwarding there, or just wait until upstream has included it?