Bug 619994 – sys-auth/elogind-229.3 : /.../ccYhKf1V.ltrans0.ltrans.o:<artificial>:function main: error: undefined reference to 'elogind_set_program_name'

• Product: Gentoo Linux
• Status: RESOLVED TEST-REQUEST

[Description Toralf Förster 2017-05-28 10:59:35 UTC]

libtool: link: x86_64-pc-linux-gnu-gcc -pipe -Wall -Wextra -Wundef -Wformat=2 -Wformat-security -Wformat-nonliteral -Wlogical-op -Wmissing-include-dirs -Wold-style-definition -Wpointer-arith -Winit-self -Wdeclaration-after-statement -Wfloat-equal -Wsuggest-attribute=noreturn -Werror=missing-prototypes -Werror=implicit-function-declaration -Werror=missing-declarations -Werror=return-type -Wstrict-prototypes -Wredundant-decls -Wmissing-noreturn -Wshadow -Wendif-labels -Wstrict-aliasing=2 -Wwrite-strings -Wno-unused-parameter -Wno-missing-field-initializers -Wno-unused-result -Wno-format-signedness -Werror=overflow -Wdate-time -Wnested-externs -ffast-math -fno-common -fdiagnostics-show-option -fno-strict-aliasing -fvisibility=hidden -fstack-protector -fstack-protector-strong -fPIE --param=ssp-buffer-size=4 -Werror=shadow -flto -ffunction-sections -fdata-sections -O2 -pipe -march=native -Wall -Wl,--gc-sections -Wl,--no-undefined -Wl,-z -Wl,relro -Wl,-z -Wl,now -pie -Wl,-fuse-ld=gold -Wl,-O1 -o test-login src/libelogind/sd-login/test-login.o  -Wl,--as-needed ./.libs/libshared.a -ldl -lm -lresolv -ludev -lacl -lcap -pthread
/var/tmp/portage/sys-auth/elogind-229.3/temp/ccYhKf1V.ltrans0.ltrans.o:<artificial>:function main: error: undefined reference to 'elogind_set_program_name'

  -------------------------------------------------------------------

  This is an unstable amd64 chroot image at a tinderbox (==build bot)
  name: 13.0-libressl_20170527-175314

  -------------------------------------------------------------------

gcc-config -l:
 [1] x86_64-pc-linux-gnu-6.3.0 *

Available Python interpreters, in order of preference:
  [1]   python3.4
  [2]   python2.7 (fallback)

[Comment 1 Toralf Förster 2017-05-28 10:59:38 UTC]

Created attachment 474536 [details]
emerge-info.txt

[Comment 2 Toralf Förster 2017-05-28 10:59:42 UTC]

Created attachment 474538 [details]
config.log.tbz2

[Comment 3 Toralf Förster 2017-05-28 10:59:45 UTC]

Created attachment 474542 [details]
emerge-history.txt

[Comment 4 Toralf Förster 2017-05-28 10:59:48 UTC]

Created attachment 474544 [details]
environment

[Comment 5 Toralf Förster 2017-05-28 10:59:51 UTC]

Created attachment 474546 [details]
etc.portage.tbz2

[Comment 6 Toralf Förster 2017-05-28 10:59:54 UTC]

Created attachment 474548 [details]
sys-auth:elogind-229.3:20170528-103529.log

[Comment 7 Toralf Förster 2017-05-28 10:59:58 UTC]

Created attachment 474550 [details]
temp.tbz2

[Comment 8 Sven Eden 2017-05-31 13:12:35 UTC]

I just rebuilt elogind-229.3 with your exact configure call, and it built flawlessly, using gcc-6.3.0.

The resulting differences between both calls to libtool are:

1) -flto -ffunction-sections -fdata-sections
2) -Wl,--gc-sections -Wl,-O1

I have everything else, too.

As systemd enforces the usage of the gold linker, let's see whether the LTO enforcement is creating the issue here.

Results:
- Adding 1) to CFLAGS does not lead to any problems.
- Adding 2) to LDFLAGS does not lead to any problems.

I am sorry, but apart from me having '-ftree-vectorize' in the CFLAGS, there is no difference now, and I can not reproduce your problem.

[Comment 9 Toralf Förster 2017-05-31 18:19:42 UTC]

Created attachment 474862 [details]
emerge.log.gz

elogind emerged at his image too successfully after that failure - I attached the emerge..log for completeness

[Comment 10 Sven Eden 2017-06-01 11:55:27 UTC]

If I understand the log right, it looks like:

- emerge    elogind-229.3 - FAILED
- emerge    elogind-226.4 - success
- update to elogind-229.3 - success

Weird.

I have searched for a few (ok, obvious) package upgrades between the failed and the successful merge, but nothing sticks out.
Maybe it was jut a badly written byte? Murphy's Law?

Really, I am completely at sea here, sorry.

[Comment 11 Michael Palimaka (kensington) 2017-06-06 12:10:55 UTC]

This looks like it might be LTO-related.

[Comment 12 Sven Eden 2017-06-06 16:16:55 UTC]

(In reply to Michael Palimaka (kensington) from comment #11)
> This looks like it might be LTO-related.

The weird thing is, that the systemd build system always enforced LTO where available.

@Toralf: Can you, by any chance, reproduce this error? "elogind_set_program_name()" is a function of mine to circumvent problems with musl-libc and to add debug log support for some internal parts.

[Comment 13 Michał Górny 2017-06-06 17:27:54 UTC]

(In reply to Sven Eden from comment #12)
> (In reply to Michael Palimaka (kensington) from comment #11)
> > This looks like it might be LTO-related.
> 
> The weird thing is, that the systemd build system always enforced LTO where
> available.

...and the systems team disabled it as soon as they noticed.

[Comment 14 Sven Eden 2017-06-07 09:31:50 UTC]

(In reply to Michał Górny from comment #13)
> (In reply to Sven Eden from comment #12)
> > (In reply to Michael Palimaka (kensington) from comment #11)
> > > This looks like it might be LTO-related.
> > 
> > The weird thing is, that the systemd build system always enforced LTO where
> > available.
> 
> ...and the systems team disabled it as soon as they noticed.

Maybe, but LTO worked on all my machines with gcc-4.9.x, gcc-5.3.0 and now gcc-6.3.0 flawlessly.

However, I *think* I found the reason. Let me do some experiments...

[Comment 15 Sven Eden 2017-06-08 10:11:16 UTC]

Two updates:

1) I think I found the reason. The fix will be included in version 231.
2) elogind, contrary to systemd, supports
  configure --disable-lto
   -> Please use this when in doubt.

However, I am still not able to reproduce the issue, so 1) is guesswork.

Hopefully someone can provide a reproducible way to trigger the linker error.

[Comment 16 Sven Eden 2017-06-12 13:58:58 UTC]

(In reply to Sven Eden from comment #15)
> 1) I think I found the reason. The fix will be included in version 231.

I have backported the possible "fix" to v229.5 and opened a version bump request as bug 621596.

Could you please test whether the issue remains once elogind is bumped to v229.5? It *should* be fixed now.