Bug 829144

Summary:	app-misc/vcontrold-0.98.10 fails to compile with -fno-common: ld.lld: error: duplicate symbol: TxRx
Product:	Gentoo Linux	Reporter:	Agostino Sarubbo <ago>
Component:	Current packages	Assignee:	Tobias Leupold <tl>
Status:	RESOLVED UPSTREAM
Severity:	normal	CC:	proxy-maint, sam
Priority:	Normal	Keywords:	PATCH
Version:	unspecified
Hardware:	All
OS:	Linux
Whiteboard:
Package list:		Runtime testing required:	---
Bug Depends on:
Bug Blocks:	705764
Attachments:	build.log Patch to fix the clang build

Description Agostino Sarubbo gentoo-dev

2021-12-14 08:52:17 UTC

https://blogs.gentoo.org/ago/2020/07/04/gentoo-tinderbox/

Issue: app-misc/vcontrold-0.98.10 fails to compile.
Discovered on: amd64 (internal ref: tinderbox)

NOTE:
This machine uses clang as a compiler and lld as a linker

Comment 1 Agostino Sarubbo gentoo-dev

2021-12-14 08:52:19 UTC

Created attachment 758848 [details]
build.log

build log and emerge --info

Comment 2 Tobias Leupold 2021-12-14 11:10:04 UTC

Thanks for your report! I'll see if I can reproduce this and file an upstream bug report.

Comment 3 Agostino Sarubbo gentoo-dev

2021-12-14 11:23:03 UTC

This is a simply -fno-common issue.

With gcc, -fcommon is appended and the bug is not visible.

With clang/lld I don't see -fcommon in the build so the bug is reproducible.

Comment 4 Tobias Leupold 2021-12-14 12:03:35 UTC

Created attachment 758929 [details, diff]
Patch to fix the clang build

Actually, the build system sets -fcommon for GCC >= 10, but not for clang. I pushed the attached patch upstream ( https://github.com/openv/vcontrold/commit/b68ba0b5194a0e7a430b6a0e12070c25e36c2c67 ), so this will be part of the next release.

Thanks for reporting this and tracking this down!

Comment 5 Sam James archtester

2021-12-14 12:05:56 UTC

(In reply to Tobias Leupold from comment #4)
> Created attachment 758929 [details, diff] [details, diff]
> Patch to fix the clang build
> 
> Actually, the build system sets -fcommon for GCC >= 10, but not for clang. I
> pushed the attached patch upstream (
> https://github.com/openv/vcontrold/commit/
> b68ba0b5194a0e7a430b6a0e12070c25e36c2c67 ), so this will be part of the next
> release.
> 
> Thanks for reporting this and tracking this down!

Wow, thanks a lot for your speedy responses! Really impressive.

Comment 6 Tobias Leupold 2021-12-18 08:47:23 UTC

Just FYI: We meanwhile fixed the root cause for this and got rid of the need to use -fcommon at all :-)