Bedevilled by powerdevil-5.10.4

miket · Posted: Sun Aug 27, 2017 7:15 pm Post subject: Bedevilled by powerdevil-5.10.4

Oh, what fun in rebuilding KDE with GCC 5. I've looked in forum threads about problems with GCC 5, but this problem seems different enough that what was reported in other threads for me to start one here.

I updated all packages depending on libstdc++.so.6 as indicated in the GCC upgrade guide and I rebuilt powerdevil (with a considerable degree of builiding things just built) using the --emptytree flag. The only things showing up in a --depclean run are old versions of gentoo-sources and gcc that I left around. Even so, there is a still a problem. Here is the crazy set of error messages from the build of kde-plasma/powerdevil-5.10.4:5:

fedeliallalinea · Posted: Sun Aug 27, 2017 7:23 pm Post subject:

You use gold linker? If yes see here
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miket · Posted: Sun Aug 27, 2017 9:06 pm Post subject:

Hu · Moderator Joined: 06 Mar 2007 Posts: 21607

Gold is part of sys-devel/binutils. Could you post your emerge --info so we can get a general sense of your system configuration?

miket · Posted: Mon Aug 28, 2017 12:06 am Post subject:

Oh, my! I've heard a lot of back-and-forth about the Gold linker, of how it was connected to the LLVM project and Clang and of how there have been difficulties with them as well as added efficiencies, but I was under the impression that I'd have to install that support explicitly if I wanted to have it. I thought of the effort as being part of an alternate toolchain. Somehow I missed the bit about Gold being accepted into the GNU mainstream! I read bug reports for Gold complaining about that particular duplicate-symbol error, but I thought that since I had not "bought" any Gold that that would not be my problem. So much for assumptions. Sure enough, /usr/bin/ld.gold is in my system.

Here's the emerge --info:

miket · Posted: Mon Aug 28, 2017 12:41 am Post subject:

I see that two days ago sys-devel/binutils-2.28.1 was stabilized for amd64. I had been doing this upgrade on a single syncing of Portage done a couple of days before that--I wanted to avoid an added element of churn in the process. Would this version help? I would think, though, that the patch to the Gold bug of version 2.27 would have been fixed by the 2.28-r2 that I have now.

miket · Posted: Tue Aug 29, 2017 12:29 pm Post subject:

What's this stuff with Gold? The system ought to be awfully clean: synced portage, got binutils 2.28.1 plus other new things with emerge --deep --update @world. Eselected the new binutils, re-sourced /etc/profile, tried rebuilding only the packages implicated in the linker error message (qtwidgets, qtx11extras, qtgui, and qtcore), but powerdevil still failed to build. Next tried the bigger gun: unmerged the old version of binuitls (along with all other old stuff) with emerge --depclean, did a rebuild of all of @system, and did a full emptytree rebuild of the dependencies of powerdevil. And still it failed:

Hu · Moderator Joined: 06 Mar 2007 Posts: 21607

Sorry, I don't use gold directly nor use these packages. I hoped that your emerge --info would show a culprit, but I see nothing relevant there. I have no further ideas.

miket · Posted: Thu Aug 31, 2017 2:38 pm Post subject:

I'm stuck too. It seems that it is the ebuild that chooses the linker. I went on to try again from a clean start: a base system with no KDE. Did an emerge of of kde-plasma/plasma-meta--and still ended up in the same error. I looked at the symbol tables of the .so's named in the error message and found no such duplicated symbols. I looked at the command that resulted in the error message and saw no duplicate .o files being injected:

Josef.95 · Advocate Joined: 03 Sep 2007 Posts: 4552 Location: Germany

miket · Posted: Sat Sep 02, 2017 1:27 am Post subject:

miket · Posted: Tue Sep 05, 2017 4:46 am Post subject:

Finally! I've found a way to get powerdevil to build correctly--and three more ways for things to fail

First thing I started out doing a couple of days ago was to try the keyworded GCC versions 6.3.0 and 6.4.0. In both cases I had a build error relatively early in the process; I never made it to powerdevil. For both versions I did an emerge -vae @installed after having done the normal steps for switching between GCC versions. I didn't want to go too far into having to debug these other problems since I was dealing with keyworded GCC versions that have a lot of bugs filed against them (both versions failed on the build for dev-util/ragel-6.7-r1, for what it's worth).

Finally I decided to go the radical route. I found an old stage-3 tarball with GCC 4.9.3, masked versions of GCC later than 4.9.4, and then rebuilt @system with the target set of USE flags and did a round of depclean, preserved-rebuild, and revdep-rebuild. So now I had an up-to-date close-to-stage3 system set with GCC 4.9.4 and the needed USE flags.

Now came a big emerge for @world set items--a few utilities plus plasma-meta. This one built, powerdevil and all! One of the elog messages pointed to problems with using an older version of GCC, but the linked bug report indicated this was a problem only when the user had mixed ABI's and was certainly not the case here.

So now I tried completing the circle: switch to GCC 5.4.0-r3 and do the big rebuild. This was now in a system that had never experienced a KDE upgrade, so things must now be pretty clean--I thought.

As it happened, powerdevil again failed to build with GCC 5.4.0-r3. Same error message. I may not have isolated the actual error, but now I know what neighborhood it lives in.

So now I ask: has anyone ever had success in building kde-plasma/powerdevil using GCC 5.4.0.r3?

I've heard that some people have had success with GCC 7. Sigh, maybe I'll try that.

asturm · Developer Joined: 05 Apr 2007 Posts: 8935

fedeliallalinea · Posted: Tue Sep 05, 2017 8:52 am Post subject:

miket · Posted: Wed Sep 06, 2017 5:17 pm Post subject:

asturm · Developer Joined: 05 Apr 2007 Posts: 8935

geki · Posted: Sat Dec 23, 2017 7:45 pm Post subject:

I have this issue currently with qtdeclarative's particlesplugin and qtgui throwing up on linking with that .......
I just removed qtgui from linker to succeed. That plugin luckily just needs qtgui header code. :twisted:

There is an upstream report[0][1] wrt gold linker. Any ideas?

[0] https://bugreports.qt.io/browse/QTBUG-63083
[1] https://codereview.qt-project.org/#/c/204936/3/recipes-qt/qt5/qtbase_git.bb,unified

My emerge info. (My default ld is ld.bfd.)

geki · Posted: Sat Dec 23, 2017 8:03 pm Post subject:

Maybe this. Time to rebuild?!
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geki · Posted: Sat Dec 23, 2017 11:19 pm Post subject:

Guess we have to wait for patches from Fedora to be applied in Gentoo's binutils or for binutils 2.30.

See my comment at https://bugs.gentoo.org/623566#c32
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