Bug 915833

Summary:	media-libs/libraw-0.20.1[openmp] clang profile: /usr/lib64/libraw.so.23: undefined symbol: __kmpc_global_thread_num
Product:	Gentoo Linux	Reporter:	Arniii <lg3dx6fd>
Component:	Current packages	Assignee:	No maintainer - Look at https://wiki.gentoo.org/wiki/Project:Proxy_Maintainers if you want to take care of it <maintainer-needed>
Status:	UNCONFIRMED ---
Severity:	normal	CC:	koron393, sam
Priority:	Normal
Version:	unspecified
Hardware:	All
OS:	Linux
See Also:	https://github.com/LibRaw/LibRaw/pull/633 https://bugs.gentoo.org/show_bug.cgi?id=740310
Whiteboard:
Package list:		Runtime testing required:	---
Bug Depends on:
Bug Blocks:	881311, 896220, 915852
Attachments:	startx -> dbus-launch --exit-with-session startplasma-wayland

Description Arniii 2023-10-15 21:29:24 UTC

Created attachment 872945 [details]
startx -> dbus-launch --exit-with-session startplasma-wayland

clang profile

attaching example of when it happens ( one example )

such errors seems to be found by tinderbox with another case.

after googling it seems to be a problem of linking against openmp runtime.

emerging with USE="-openmp" solves it, what proves the point above.

Also, it seems someone got the same with tinderbox : https://bugs.gentoo.org/408963#c8

maybe it's clang's openmp issue ?

anyway, link the issue somehow with clang-systemwide: https://bugs.gentoo.org/408963

Comment 1 Sam James archtester

2024-03-24 08:16:23 UTC

(See bugs which depend on this too.)

I can't reproduce this yet but I guess the openmp flags aren't getting passed correctly when linking.

Their copy of AX_OPENMP in m4/openmp.m4 is kind of old so might be worth refreshing that from autoconf-archive.

Comment 2 Sam James archtester

2024-03-24 08:45:53 UTC

(In reply to Sam James from comment #1)
> [...]
> Their copy of AX_OPENMP in m4/openmp.m4 is kind of old so might be worth
> refreshing that from autoconf-archive.

Sent https://github.com/LibRaw/LibRaw/pull/633 upstream for this bit.

Comment 3 Sam James archtester

2024-03-24 08:49:52 UTC

Hm, with USE=openmp (no -fopenmp* in *FLAGS), my /usr/lib64/libraw_r.so.23.0.0 indeed isn't linked with libomp (or libgomp).

Comment 4 Koron Naga 2024-04-02 13:46:29 UTC

I encountered a similar problem when open the gwenview.

---
plasmashell[273640]: /usr/bin/gwenview: symbol lookup error: /usr/lib64/libraw.so.23: undefined symbol: __kmpc_global_thread_num
---

I solved it by adding "-lomp" to LDFLAGS and re-merging media-libs/libraw-0.21.2

---
LDFLAGS="${LDFLAGS} -lomp"
---

This seems to often happen when using OpenMP with CLANG.